JP6563239B2 - Adiabatic quantum flux parametron circuit and superconducting logic device - Google Patents

Description

  The present invention relates to an adiabatic quantum flux parametron circuit (AQFP circuit) and a superconducting logic element.

  Superconducting integrated circuits use magnetic flux quanta as an information medium, and perform signal processing such as logical operations and storage with low power consumption and high speed. In a superconducting integrated circuit, a superconducting wiring having zero DC resistance is used as a wiring, and a Josephson junction is used as a switching element constituting a logic circuit.

  As a superconducting integrated circuit, a single flux quantum circuit (SFQ circuit) using superconductivity and an adiabatic flux quantum parametron circuit (AQFP circuit) are known. Superconducting integrated circuits include, for example, superconducting integrated circuits, digital integrated circuits such as processors and DSPs, and superconducting integrated circuits such as A / D converter circuits, D / A converter circuits, and voltage standard circuits. A circuit or the like can be configured.

  The adiabatic quantum flux parametron circuit includes a superconducting transformer as a configuration for propagating an output signal.

  The adiabatic quantum flux parametron circuit malfunctions due to stray magnetic coupling between the power supply line and signal line in the circuit or between the power supply line and the superconducting transformer, resulting in unstable logic operation. It is known.

  FIG. 13 is a diagram for explaining a configuration example of a conventional adiabatic quantum flux parametron circuit. FIGS. 13A and 13B show schematic configurations, and FIG. 13A shows a primary side in a superconducting transformer. The state where the inductance and the secondary side inductance are overlapped is shown, and FIG. 13B shows the state where the secondary side inductance is separated for explanation. FIG. 13C shows an equivalent circuit.

  The adiabatic quantum flux parametron circuit 101 includes a superconducting quantum interference device (SQUID) 102, a power supply line 103, and a superconducting transformer 104. The superconducting quantum interference device 102 includes two Josephson junctions 102a and 102b (J1, J2) in the superconducting ring 102d with the central node 102c interposed therebetween, and a magnetic flux induced by the power supply line 103 is applied.

  The superconducting quantum interference device 102 determines the logic state according to the input signal Iin and amplifies the current. The superconducting transformer 104 includes a primary side wiring 104a and a secondary side wiring 104b, and outputs an output of the superconducting quantum interference device 102 as an output signal Iout from the output terminal 104c.

  The magnetic flux induced by the excitation current (bias current) Ix of the power supply line 103 intersects the primary side inductance Lq and the secondary side inductance Lout of the superconducting transformer 104 to perform floating magnetic coupling. Lx and the primary side inductance Lq are magnetically coupled with a coupling coefficient Kxq, and the inductance Lx of the power line 103 and the secondary side inductance Lout are magnetically coupled with a coupling coefficient Kxout. The stray magnetic coupling between the power supply line 103 and the superconducting transformer 104 causes the adiabatic quantum flux parametron circuit 101 to malfunction. In FIG. 13C, coupling coefficients Kxq and Kxout indicated by broken lines represent stray magnetic coupling between the power supply line 103 and the superconducting transformer 104.

  The inventor of the present invention has proposed a configuration in which a superconducting shield is provided in a superconducting transformer in order to solve the problem of instability of logic operation due to floating magnetic coupling (Non-patent Document 1).

  FIG. 14 is a diagram for explaining an adiabatic quantum flux parametron circuit provided with a superconducting shield. FIG. 14A shows a schematic configuration, FIG. 14B shows a layer state of a superconducting transformer and a superconducting shield provided on the ground plane, and FIG. 14C shows a circuit configuration. A superconducting shield 110 is provided so as to cover the upper part of the superconducting transformer 104, and magnetic coupling between the superconducting transformer 104 and the power supply line 103 is cut off.

  By providing superconducting shield 110 in superconducting transformer 104, coupling coefficient Kxq between inductance Lx of power supply line 103 and primary side inductance Lq of superconducting transformer 104, and inductance Lx of power supply line 103 and superconducting transformer 104 The coupling coefficient Kxout with the secondary side inductance Lout is suppressed. FIG. 14B shows a state where the magnetic coupling of the coupling coefficient Kxq and the coupling coefficient Kxout is suppressed, and the floating magnetic coupling shown by the broken line in FIG. 13C is canceled.

  The superconducting shield 110 suppresses the magnetic coupling of the coupling coefficient Kxq and the coupling coefficient Kxout, and reduces the coupling coefficient Kout between the primary side inductance Lq and the secondary side inductance Lout in the superconducting transformer 104. This reduction of the coupling coefficient Kout reduces the output level of the superconducting transformer 104.

"Design and demonstration of adiabatic quantum-flux-parameter on logic circuits with superconductor magnetic shields" Kenta Inoue, Naoki Takeuchi, Tatsuya Narama, Yuki Yamanashi, Nobuyuki Yoshikawa Superconductor Science and Technology 28 (2015) 045020 IOP Publishing

  Although the superconducting transformer is provided with a superconducting shield, it can suppress unnecessary stray magnetic coupling in the adiabatic quantum flux parametron circuit, but the superconducting shield provides a gap between the primary side inductance and the secondary side inductance. Decrease the coupling coefficient to reduce the magnetic coupling. This decrease in magnetic coupling leads to a decrease in the output level of the adiabatic quantum flux parametron circuit, so that the logic operation of the adiabatic quantum flux parametron circuit becomes unstable and the operating margin is reduced, or the sufficient output level is reduced. There is a problem that the wiring length cannot be increased because it cannot be obtained.

  Therefore, the present invention solves the above-mentioned conventional problems and eliminates unnecessary floating in the adiabatic quantum flux parametron circuit without reducing the coupling coefficient between the primary side inductance and the secondary side inductance of the superconducting transformer. The purpose is to suppress the effects of magnetic coupling.

  In addition, to suppress unnecessary magnetic coupling in the adiabatic quantum flux parametron circuit, and to reduce the operating margin of the adiabatic quantum flux parametron circuit and limit the wiring length as an output level sufficient for stable logic operation. With the goal.

  According to the present invention, a superconducting transformer provided in an adiabatic quantum magnetic flux parametron circuit is constituted by a pair of transformer parts, and two transformers are formed by floating magnetic coupling with a power supply line by arrangement of the pair of transformer parts and a wiring pattern of the transformer part. The direction of the current generated in the part is opposite to the coupling part of the two transformer parts, and the current generated by the stray magnetic coupling with the power supply line is canceled out by the coupling part, so that in the adiabatic quantum flux parametron circuit In FIG. 5, the floating magnetic coupling between the power line and the superconducting transformer is substantially eliminated, and the malfunction of the logic operation of the adiabatic quantum flux parametron circuit due to the floating magnetic coupling is eliminated.

  In the superconducting transformer of the present invention, the configuration in which the currents flowing in the pair of transformer parts in opposite directions due to the stray magnetic coupling with the power supply line is the coupling between the primary side inductance and the secondary side inductance of the superconducting transformer. Since the coefficient is not affected, the coupling coefficient between the primary side inductance and the secondary side inductance of the superconducting transformer does not decrease, and the output level does not decrease.

  The adiabatic quantum flux parametron circuit of the present invention includes a superconducting quantum interference element (SQUID) having two Josephson junctions sandwiching a central node in a superconducting ring, a power line for inducing a magnetic flux in the superconducting quantum interference element, And a superconducting transformer that outputs a current of the superconducting quantum interference device (SQUID).

  The adiabatic quantum flux parametron circuit of the present invention amplifies an input current by a superconducting quantum interference device (SQUID), and propagates a signal to a superconducting logic device in the next stage by a superconducting transformer.

  The superconducting transformer includes a pair of transformer units each having a primary wiring and a secondary wiring. In the pair of transformer units, the pair of primary-side wirings connect both input ends of the pair of wirings to the central node of the superconducting quantum interference device, and pair the primary-side wirings by magnetic coupling with the power supply line. The directions of currents induced in the wirings are opposite to each other with respect to the input ends of the pair of wirings. In addition, the pair of wires of the secondary side wire connects both output ends of the pair of wires to the output end of the adiabatic quantum flux parametron circuit, and the pair of wires of the secondary side wire by magnetic coupling with the power source line. The directions of currents induced by the two are opposite to each other with respect to the output ends of the pair of wires.

  Magnetic flux induced by the excitation current of the power supply line is applied to both wirings of the pair of transformer parts, but the direction of the current induced in each wiring of the pair of transformer parts by the magnetic flux is connected to the coupling part where the wirings are coupled. On the other hand, both currents are canceled by making the directions opposite to each other. This substantially eliminates the floating magnetic coupling between the power line and the superconducting transformer in the adiabatic quantum flux parametron circuit, and eliminates the malfunction of the logic operation of the adiabatic quantum flux parametron circuit due to the floating magnetic coupling. .

(Configuration of superconducting transformer)
In the adiabatic quantum magnetic flux parametron circuit of the present invention, the superconducting transformer can be configured in a plurality of forms depending on the arrangement of the pair of transformer parts and the wiring pattern of the transformer part.

First configuration of the superconducting transformer:
In the first configuration of the superconducting transformer, the arrangement of the pair of transformer parts is parallel to the direction of the power supply line on the same side with respect to the power supply line, and the primary side wiring and the secondary of the pair of transformer parts The wiring pattern of the side wiring is opposite to the direction of the magnetic flux induced by the magnetic coupling with the power supply line. As a result, the directions of currents induced in the wirings of the pair of transformer parts are opposite to each other with respect to the coupling part where the wirings are coupled.

  Further, in the wiring pattern of the transformer part, the wiring patterns of the primary side wiring and the secondary side wiring of the pair of transformer parts are symmetric with respect to a straight line orthogonal to the power supply line.

  The pair of transformer sections are arranged in parallel with each other in the direction of the power supply line in a configuration in which they are opposite to each other with respect to the direction of the magnetic flux induced by the magnetic coupling with the power supply line on the same side with respect to the power supply line. Therefore, the direction of the magnetic flux induced by the excitation current of the power supply line is the same direction. In addition, since the wiring patterns of the pair of transformer parts are opposite to the direction of the magnetic flux induced by the magnetic coupling with the power supply line, the direction of the current generated in the wiring pattern by the magnetic flux in the same direction is the current coupling. Currents input in opposite directions cancel each other in the coupling portion at the input end of the primary wiring and the coupling portion at the output end of the secondary wiring.

Second configuration of the superconducting transformer:
In the second configuration of the superconducting transformer, the arrangement of the pair of transformer parts and the wiring patterns of the primary side wiring and the secondary side wiring of the pair of transformer parts are point-symmetric on the opposite side across the power supply line.

  Since the pair of transformers are arranged at the point of contrast on the opposite side of the power supply line on the opposite side of the power supply line, the direction of the magnetic flux induced by the excitation current of the power supply line is the same direction. In addition, since the wiring pattern of the pair of transformer parts is point-contrast on the opposite side across the power supply line across the power supply line, the direction of the current generated in the wiring pattern by the magnetic flux in the same direction is the current coupling part On the other hand, currents input in opposite directions are canceled out at the coupling portion at the input end of the primary wiring and the coupling portion at the output end of the secondary wiring.

Third configuration of the superconducting transformer:
In the third configuration of the superconducting transformer, the arrangement of the pair of transformer parts is formed by laminating at the same position with respect to the direction of the power supply line on the same side across the power supply line, and the wiring pattern of the pair of transformer parts Is in a horizontally reversed relationship with respect to the plane including the power supply line.

  Since the pair of transformer units are arranged in the same position in the direction of the power supply line on the same side across the power supply line, the magnetic flux induced by the excitation current of the power supply line is in the opposite direction. In addition, since the wiring pattern of the pair of transformer parts is symmetrical with respect to the plane including the power supply line, the directions of currents generated in the wiring pattern by the magnetic flux induced in the opposite direction are opposite to each other with respect to the current coupling part. The current input in the opposite direction cancels out at the coupling portion at the input end of the primary wiring and the coupling portion at the output end of the secondary wiring.

  By setting the arrangement of the pair of transformer units and the wiring pattern of the transformer unit by the first configuration, the second configuration, and the third configuration described above, the magnetic flux induced by the excitation current of the power source line is set. The directions of the currents can be opposite to each other with respect to the coupling part of both wirings of the pair of transformer parts, so that the current flowing through the transformer part can be offset by floating magnetic coupling.

  In the above-described superconducting transformer, the inductance of the secondary side wiring is set to be larger than the inductance of the primary side wiring. The configuration in which the inductance of the secondary wiring is made larger than the inductance of the primary wiring is such that the primary wiring is longer than the primary wiring in the opposing arrangement of the primary wiring and the secondary wiring. And / or by making the wiring width of the secondary wiring smaller than the wiring width of the primary wiring.

  By configuring the secondary transformer as described above, the ratio of the secondary inductance to the primary inductance of the superconducting transformer is set to be large, thereby reducing the back action current that returns to the input terminal of the adiabatic quantum flux parametron circuit. The output level output from the output end of the adiabatic quantum flux parametron circuit can be increased.

(Form of superconducting logic device using adiabatic quantum flux parametron circuit)
By using the adiabatic quantum flux parametron circuit of the present invention, a plurality of types of superconducting logic elements can be constructed.

First form of superconducting logic element:
The first form of the superconducting logic element is a form having a buffer function. The buffer logic element has an input line connected to the central node, and the wiring pattern of the pair of transformer units is configured to output a current in the same direction as the current direction from the output terminal of the secondary wiring to the input terminal. With this configuration, a buffer function for outputting a current in the same direction as the current direction of the input line can be achieved.

Second form of superconducting logic element:
A second form of the superconducting logic element is a form having a NOT function. The NOT logic element has an input line connected to the central node, and the wiring pattern of the pair of transformer units is configured to output a current in a direction opposite to the current direction of the input line from the output end of the secondary side wiring. With this configuration, a NOT function of outputting a current in the direction opposite to the current direction of the input line can be achieved.

Third form of superconducting logic element:
The third form of the superconducting logic element is a form having a constant function. The constant logic element is formed by disconnecting the input line from the central node and configuring the superconducting quantum interference element (SQUID) asymmetrically with respect to the central node and / or asymmetrical superconducting transformer. can do. With this configuration, it is possible to achieve a constant function that always outputs a current in a certain direction during excitation when an excitation current is applied to the power supply line.

Fourth form of superconducting logic element:
The fourth form of the superconducting logic element is a form that exhibits a branch function for connecting the buffer logic element, the NOT logic element, the constant logic element, and the like shown in the first to third superconducting logic elements. . The branch logic element has a function of outputting a majority logic for a plurality of inputs or a mechanism for dividing one input into a plurality of outputs. The branch logic element includes a plurality of wiring portions composed of two wirings, and connects one of the plurality of wiring portions. In each wiring part, two wirings connect each end, and one of both connection ends is an input end and the other is an output end. The two wirings cause the current directions of both wirings induced by the current of the power supply line to be opposite to the connecting portion of the two wirings, and the currents induced in both wirings by the power supply line current cancel each other.

  In addition, by making the wiring lengths of the plurality of wiring portions equal, the inductances of the wiring portions in the branch logic element can be matched, and the magnitudes of the signal currents flowing through the wiring portions can be made uniform. Majority logic is possible by matching the signal levels from each element.

  The superconducting logic element constitutes a logic circuit having a MAJ function and a NAND function for inputting signals of a plurality of superconducting logic elements and outputting a majority logic state in connection between the superconducting logic elements, A logic circuit having an SPL function for dividing one input signal can be configured.

  As described above, according to the adiabatic quantum flux parametron circuit of the present invention, the inside of the adiabatic quantum flux parametron circuit without reducing the coupling coefficient between the primary side inductance and the secondary side inductance of the superconducting transformer. The influence of unnecessary floating magnetic coupling can be suppressed.

  In addition, to suppress unnecessary magnetic coupling in the adiabatic quantum flux parametron circuit, and to reduce the operating margin of the adiabatic quantum flux parametron circuit and limit the wiring length as an output level sufficient for stable logic operation. Can do.

It is the schematic for demonstrating schematic structure of the heat insulation type quantum flux parametron circuit of this invention. It is the schematic for demonstrating the electric current state of the heat insulation type quantum flux parametron circuit of this invention. It is the schematic for demonstrating arrangement | positioning of the trans | transformer part of the 1st structure of the heat insulation type quantum magnetic flux parametron circuit of this invention. It is the schematic for demonstrating the wiring pattern of the trans | transformer part of the 1st structure of the heat insulation type quantum flux parametron circuit of this invention. It is a figure for demonstrating optimization of a superconducting transformer. It is a figure for demonstrating the simulation result of an output current. It is a figure for demonstrating the 2nd structure of the heat insulation type | mold quantum magnetic flux parametron circuit of this invention. It is a figure for demonstrating the 3rd structure of the adiabatic type quantum flux parametron circuit of this invention. It is a figure for demonstrating the structural example of the superconducting logic element provided with the function of NOT. It is a figure for demonstrating the structural example of the superconducting logic element provided with the function of a constant. It is a figure for demonstrating the structural example of the superconducting logic element provided with the function of a branch. It is a figure for demonstrating the structural example of the superconducting logic element using the adiabatic-type quantum magnetic flux parametron circuit of this invention. It is a figure for demonstrating the structural example of the conventional adiabatic-type quantum magnetic flux parametron circuit. It is a figure for demonstrating the heat insulation type quantum flux parametron circuit which provided the superconducting shield.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Hereinafter, the schematic configuration of the adiabatic quantum flux parametron circuit of the present invention will be described with reference to FIGS. 1 and 2, and the first configuration of the adiabatic quantum flux parametron circuit of the present invention will be described with reference to FIGS. The optimization of the superconducting transformer is explained using FIG. 5, the simulation result of the output current is explained using FIG. 6, the second configuration of the adiabatic quantum flux parametron circuit is explained using FIG. 8, a third configuration of the adiabatic quantum flux parametron circuit of the present invention will be described, and a superconducting logic element using the adiabatic quantum flux parametron circuit of the present invention will be described with reference to FIGS.

[Schematic configuration of adiabatic quantum flux parametron circuit]
FIG. 1 is an equivalent circuit for explaining a schematic configuration of an adiabatic quantum flux parametron circuit of the present invention. The equivalent circuit shown in FIG. 1 shows an example of an adiabatic quantum magnetic flux parametron circuit that constitutes the superconducting logic element of the buffer, and FIG. 1 (b) shows the power line and the transformer wiring in FIG. 1 (a). It shows a state in which the magnetic coupling between the two is suppressed. FIG. 2 is a diagram for explaining the current state of the adiabatic quantum flux parametron circuit of the present invention.

  The adiabatic quantum flux parametron circuit 1 includes a superconducting quantum interference device (SQUID) 2, a power supply line 3, and a superconducting transformer 4. A superconducting quantum interference device (SQUID) 2 includes two Josephson junctions 2a and 2b (J1, J2) in a superconducting ring 2d with a central node 2c interposed therebetween. The power line 3 applies a magnetic flux induced by the excitation current Ix to the superconducting quantum interference device (SQUID) 2. The superconducting quantum interference device (SQUID) 2 determines the logic state according to the input signal Iin input from the input terminal 1a of the adiabatic quantum flux parametron circuit 1 when the excitation current Ix of the power supply line 3 is applied. The output signal Iout in the current direction according to the logic state is output.

  When an excitation current Ix flows through the power supply line 3, an output signal is generated according to the input signal Iin input from the input terminal 1a due to magnetic coupling between the inductance Lx of the power supply line 3 and the inductances L1 and L2 of the superconducting ring 2d. Iout is output. Here, the coupling coefficients between the inductance Lx of the power supply line 3 and the inductances L1 and L2 of the superconducting ring 2d are K1 and K2, respectively.

  The superconducting transformer 4 inputs the signal of the superconducting quantum interference device (SQUID) 2 from the input terminal 4in, and outputs it from the output terminal 4out through the transformer. The superconducting transformer 4 includes a pair of transformer parts 4A and 4B.

  The transformer section 4A includes a primary side wiring 4Aa and a secondary side wiring 4Ab, and the primary side inductance Lq1 and the secondary side inductance Lout1 are magnetically coupled with a coupling coefficient Kout1. On the other hand, the transformer section 4B includes a primary side wiring 4Ba and a secondary side wiring 4Bb, and the primary side inductance Lq2 and the secondary side inductance Lout2 are magnetically coupled with a coupling coefficient Kout2.

  The pair of transformer parts 4A and 4B connect the primary side wiring 4Aa and the primary side wiring 4Ba at the input terminal 4in of the primary side inductance and are connected to the central node 2c. At the output end 4out of the secondary side wiring, the secondary side wiring 4Ab and the secondary side wiring 4Bb are connected to the output end 1b of the adiabatic quantum flux parametron circuit 1.

  The primary side wiring 4Aa and the secondary side wiring 4Ab of the transformer unit 4A and the primary side wiring 4Ba and the secondary side wiring 4Bb of the transformer unit 4B generate current due to magnetic flux induced by the excitation current Ix of the power supply line 3. The directions of the currents generated in the wirings of the transformer parts 4A and 4B are opposite to each other with respect to the coupling parts of the wirings. In order to make the currents reverse to each other, the currents of the primary wirings 4Aa and 4Ab are in the reverse direction with respect to the input terminal 4in, and the currents of the secondary wirings 4Ab and 4Bb are in the reverse direction with respect to the output terminal 4out. Arrange so that

  In the equivalent circuit of FIG. 1A, the floating magnetic coupling between the inductance Lx of the power supply line 3 and the primary side wiring 4Aa and the secondary side wiring 4Ab of the transformer section 4A is the coupling coefficient Kxq1 and the coupling coefficient Kxout1, respectively. Similarly, the floating magnetic coupling between the inductance Lx of the power supply line 3 and the primary side wiring 4Ba and the secondary side wiring 4Bb of the transformer unit 4B is expressed by a coupling coefficient Kxq2 and a coupling coefficient Kxout2, respectively. The

  In this configuration, the primary side wiring 4Aa and the secondary side wiring 4Ab of the transformer unit 4A and the primary side wiring 4Ba and the secondary side wiring 4Bb of the transformer unit 4B are arranged with respect to the direction of the magnetic flux induced by the excitation current of the power supply line 3. Thus, by arranging the current directions of the wirings of the transformer parts 4A and 4B to be opposite to each other between the transformer part 4A and the transformer part 4B, the direction of the current induced in each wiring by the floating magnetic coupling is Between the transformer unit 4A and the transformer unit 4B, the directions are opposite to each other with respect to the input end or the output end, which is a coupling portion of each wiring. Therefore, of the currents flowing through the primary side wiring 4Aa and the primary side wiring 4Bb, the currents induced by the power line current cancel each other. Further, the currents induced by the currents of the power supply lines cancel each other in the currents flowing through the secondary side wiring 4Ba and the secondary side wiring 4Bb.

  The currents induced in the primary wiring and the secondary wiring due to the floating magnetic coupling with the power supply line cancel each other by making the current direction of the pair of transformer parts opposite to the current coupling part. Therefore, the floating magnetic coupling between the inductance Lx of the power supply line 3 and the primary side wiring 4Aa and the secondary side wiring 4Ab of the transformer section 4A, and the inductance Lx of the power supply line 3 and the primary side wiring 4Ba of the transformer section 4B and The stray magnetic coupling with the secondary wiring 4Bb can be treated as being substantially suppressed. FIG. 1B shows an equivalent circuit in which floating magnetic coupling is substantially suppressed.

  In the adiabatic quantum flux parametron circuit 1 shown by the equivalent circuit in FIGS. 1A and 1B, the power supply in the state where the input signal Iin is applied to the input terminal 1 a of the adiabatic quantum flux parametron circuit 1 as an initial state. When the excitation current Ix is supplied to the line 3, the shape of the potential of the adiabatic quantum magnetic flux parametron circuit changes, and the final state of the logic element is a state where one Josephson junction is switched ("0" state), or the other Transition to either one of the switched Josephson junctions ("1" state). As a result, the current amplified by the Josephson junction switching flows through the primary wiring 4a.

  In the superconducting transformer 4, when a current flows from the superconducting quantum interference element (SQUID) 2 to the primary wiring 4a through the input terminal 4in, the secondary wiring 4b is caused by the mutual inductance between the primary wiring 4a and the secondary wiring 4b. An output current is induced in

  In the secondary side wiring 4Ab and the secondary side wiring 4Bb, currents in opposite directions flow with respect to the current coupling portion. Therefore, both currents cancel each other out at the output end 4out, and the secondary side wiring 4b and the power source The coupling coefficient Kxout of the mutual inductance due to the floating magnetic coupling with the wire 3 can be regarded as being substantially suppressed, and the influence due to the unnecessary floating magnetic coupling in the adiabatic quantum flux parametron circuit is suppressed. Is done. The current induced in the secondary side wiring 4Ab and the secondary side wiring 4Bb passes through the output terminal 4out, and then is output as an output signal Iout from the output terminal 1b of the adiabatic quantum magnetic flux parametron circuit 1.

  FIG. 2 is a diagram for explaining the current in the superconducting transformer 4 in the adiabatic quantum flux parametron circuit.

  The superconducting transformer 4 has currents IA and IB that flow due to magnetic flux induced by the excitation current Ix of the power line 3 and currents IC and ID that flow based on the output of the superconducting quantum interference device (SQUID) 2. Flowing.

  FIG. 2A shows currents IA and IB (arrows in FIG. 2A) that flow due to magnetic flux induced by the excitation current Ix of the power line 3.

  The current component IA flows due to stray magnetic coupling between the power supply line 3 and the primary side wires 4Aa, 4Ba of the superconducting transformer 4, and the current component IB flows on the secondary side wires 4Ab, 4Bb of the power source line 3 and the superconducting transformer 4. It flows by the floating magnetic coupling. The current IA is canceled out at the input terminal 4in because the current is in the reverse direction with respect to the input terminal 4in, which is a joint between the primary wirings 4Aa and 4Ba.

  The current component IB is canceled out at the output end 4out because the current is in the reverse direction with respect to the output end 4out which is the coupling portion of the secondary side wires 4Ab and 4Bb.

  Therefore, the primary wiring 4Aa and the primary wiring 4Ba are configured such that the currents induced by the currents of the power supply lines flow in opposite directions with respect to the current coupling portion, so that both currents cancel each other out at the input terminal 4in. Thus, the coupling coefficient Kxq of mutual inductance due to stray magnetic coupling between the primary wirings 4Aa, 4Ba and the power supply line 3 can be regarded as being substantially suppressed, and the adiabatic quantum flux parametron circuit The effect of unnecessary stray magnetic coupling is suppressed.

  Further, similarly to the primary side wiring 4Aa and the primary side wiring 4Ba, in the secondary side wirings 4Ab and 4Bb, currents induced by the power line current flow in opposite directions with respect to the current coupling portion. Both currents cancel each other out at the output terminal 4out, and the coupling coefficient Kxout of mutual inductance due to stray magnetic coupling between the secondary wirings 4Ab and 4Bb and the power supply line 3 can be regarded as being substantially suppressed. And the influence of unnecessary stray magnetic coupling in the adiabatic quantum flux parametron circuit is suppressed.

  FIG. 2B shows currents IC and ID (arrows in FIG. 2B) that flow based on the output of the superconducting quantum interference device (SQUID) 2.

  The current component IC flows through the input terminal 4in of the output signal of the superconducting quantum interference device (SQUID) 2, and the current component ID is magnetically coupled between the primary wirings 4Aa and 4Ba and the secondary wirings 4Ab and 4Bb. Flowing. The current component IC is divided into the primary side wires 4Aa and 4Ba at the input terminal 4in, and the current component ID is merged at the output terminal 4out which is the coupling part of the secondary side wires 4Ab and 4Bb, and the adiabatic quantum flux parametron circuit 1 Is output as an output signal Iout from the output terminal 1b.

  Hereinafter, a configuration example of the adiabatic quantum magnetic flux parametron circuit represented by the equivalent circuit of FIG. 1 will be described. Hereinafter, the first, second, and third configuration examples show the configuration example of the arrangement of the pair of transformer parts of the superconducting transformer and the wiring pattern of the transformer part. In the following description, a configuration example of the buffer logic element 10 is used as the configuration of the superconducting transformer.

(First configuration of superconducting transformer)
A first configuration of the superconducting transformer will be described with reference to FIGS. FIGS. 3A, 3B, and 3C are schematic diagrams for explaining the arrangement of the transformer section having the first configuration, and FIGS. 4A and 4B illustrate the wiring pattern of the transformer section. It is the schematic for doing.

  3 (a), 3 (b), and 3 (c) show states viewed from different viewpoints. In FIG. 3, the adiabatic quantum flux parametron circuit 1 includes a power line 3, a superconducting quantum interference element (SQUID) 2 disposed along the power line 3, and a superconducting transformer 4. The output signal of the superconducting quantum interference device (SQUID) 2 is output via The superconducting quantum interference device (SQUID) 2 is configured by providing two Josephson junctions 2a and 2b on a superconducting ring 2d with a central node 2c interposed therebetween. The adiabatic quantum flux parametron circuit 1 is formed on the ground plane G, and the magnetic flux induced by the power line 3 is formed along the ground plane G.

  In the superconducting transformer 4 of the first configuration example, a pair of transformer portions 4A and 4B are arranged in parallel along the direction of the power supply line 3 on the same side with respect to the power supply line 3. The wiring patterns of the primary side wirings 4Aa, 4Ba and the secondary side wirings 4Ab, 4Bb of the pair of transformer parts 4A, 4B are symmetrical with respect to the straight line orthogonal to the power supply line 3, thereby The directions of currents induced in the primary side wirings 4Aa and 4Ba and the secondary side wirings 4Ab and 4Bb by magnetic coupling are arranged so as to be opposite to each other with respect to the coupling portion of each wiring.

  Since the pair of transformer parts 4A and 4B are arranged in parallel along the direction of the power supply line 3 on the same side with respect to the power supply line 3, a magnetic flux in the same direction is caused by the excitation current of the power supply line 3 to each of the transformer parts 4A and 4B. Applied to 4B. On the other hand, the wiring patterns of the pair of transformers 4A and 4B are opposite to each other in the direction of the magnetic flux induced by the magnetic coupling with the power supply line 3, so that the direction of the current generated in the wiring is relative to the wiring coupling part. Therefore, the influence on the output current of the superconducting transformer and the influence on the Josephson junction in the superconducting quantum interference device are canceled out.

  4A shows a state where the primary side wiring 4a (4Aa, 4Ba) and the secondary side wiring 4b (4Ab, 4Bb) are stacked, and FIG. 4B shows the secondary side for explaining the configuration. The wiring 4b (4Ab, 4Bb) is shown separately from the primary wiring 4a (4Aa, 4Ba).

  In FIG. 4, a superconducting quantum interference device (SQUID) 2 forms a superconducting ring 2d by grounding the ends of Josephson junctions 2a and 2b.

  In FIG. 4B, in the primary side wirings 4 a and 4 b constituting the superconducting transformer 4, the primary side wiring 4 Aa and the primary side wiring 4 Ba constituting the primary side wiring 4 a are induced by magnetic coupling with the power source line 3. The current component IA (indicated by a broken line in the figure) is in the opposite direction to the coupling portion Q of each wiring. In addition, regarding the secondary side wiring 4Ab and the secondary side wiring 4Bb constituting the secondary side wiring 4b, the current component IB (indicated by a broken line in the figure) induced by the magnetic coupling with the power source line 3 is shown for each wiring. Are opposite to each other.

  On the other hand, in the primary side wiring 4a, the primary current Iq by the output of the superconducting quantum interference element (SQUID) 102 is divided into two at the coupling portion Q, and the current component IC (shown by the solid line in the figure) is divided into the primary side wiring 4Aa and the primary side. It flows to the wiring 4Ba. Further, in the secondary side wiring 4Ab and the secondary side wiring 4Bb constituting the secondary side wiring 4b, a current component ID flows due to mutual magnetic coupling between the primary side wiring 4Aa and the primary side wiring 4Ba, and the secondary side wiring 4Ab The signals are merged at the coupling portion R of the secondary wiring 4Bb, and an output signal Iout is output.

The optimization of the superconducting transformer will be described with reference to FIG.
The adiabatic quantum flux parametron circuit operates a logic element in an adiabatic manner. The adiabatic operation enables low energy consumption by slowly changing the superconducting phase of the Josephson junction.

In order to operate the logic element in an adiabatic manner, the primary inductance Lq of the superconducting transformer must be reduced. On the other hand, in order to increase the output signal Iout of the superconducting transformer, it is necessary to increase the mutual inductance M (= Kout × (Lq × Lout) ^1/2 ).

  Therefore, in order to reduce the primary inductance Lq of the superconducting transformer and increase the mutual inductance M, it is necessary to increase the secondary inductance Lout.

  The adiabatic quantum flux parametron circuit outputs an output signal from the output end and outputs a backflow current Ir from the input end. The magnitude of the reverse current Ir depends on the ratio between the secondary inductance Lout and the primary inductance Lq. In order to suppress the reverse current Ir and increase the output signal Iout, it is required to increase Lout / Lq.

  In the superconducting transformer of the present invention, in the wiring pattern of the secondary wirings 4Ab and 4Bb, the secondary inductance Lout is increased by the configuration in which the wiring length is increased or the wiring width is decreased, and the adiabatic quantum flux parametron circuit is provided. A large output signal can be obtained by adiabatic operation and switching operation with low energy consumption.

  The secondary inductance can be increased by increasing the wiring length of the secondary wiring or by reducing the wiring width. The wiring length of the secondary wiring can be increased by making the wiring pattern spiral.

  FIG. 6 shows the simulation result of the output current by comparing the configuration of the present invention with a conventional configuration provided with a superconducting shield. In FIG. 6, the output signals of the adiabatic quantum flux parametron circuit of the present invention in which the transformer parts of the superconducting transformer are arranged symmetrically and the conventional adiabatic quantum flux parametron circuit in which the superconducting transformer is magnetically shielded by a superconducting shield are shown. Iout is shown in comparison.

  In the configuration of a conventional adiabatic quantum flux parametron circuit using a superconducting shield, the coupling coefficient Kout between the primary side wiring and the secondary side wiring is 0.29, and the ratio Lout / Lq of the secondary side inductance Lout to the primary side inductance Lq is 0.9. In contrast, in the configuration of the adiabatic quantum flux parametron circuit of the present invention, the coupling coefficient Kout between the primary side wiring and the secondary side wiring is 0.45, and the ratio Lout / secondary inductance Lout to the primary side inductance Lq Lq is 3.5. The horizontal axis indicates the wiring inductance Lwire between the elements.

  This simulation result shows that the coupling coefficient Kout is improved by removing the superconducting shield.

  Further, it is shown that the ratio Lout / Lq is increased by extending the wiring length by making the wiring pattern of the secondary wiring into a spiral shape.

(Second configuration of superconducting transformer)
A second configuration of the superconducting transformer will be described with reference to FIG. FIG. 7 is a schematic diagram for explaining the arrangement of the transformer part of the second configuration and the wiring pattern of the transformer part. FIGS. 7A, 7B, and 7C are different viewpoints. The state seen from. FIG.7 (c) has shown the state seen from upper direction. Although the ground plane is not shown in FIG. 7, the ground plane is provided below the adiabatic quantum flux parametron circuit, as in the first configuration shown in FIG.

  In FIG. 7, as in the first configuration, the adiabatic quantum magnetic flux parametron circuit 1 includes a power line 3, a superconducting quantum interference device (SQUID) 2 disposed along the power line 3, and a superconducting transformer 4. Is provided. A superconducting quantum interference device (SQUID) 2 includes two Josephson junctions 2a and 2b in a superconducting ring 2d with a central node 2c interposed therebetween, and an output signal of the superconducting quantum interference device (SQUID) 2 is transmitted by a superconducting transformer 4. Propagate.

  In the superconducting transformer 4 of the second configuration example, the pair of transformer parts 4A and 4B are arranged on the opposite side to the direction of the power supply line 3 on the opposite side across the power supply line 3. The wiring patterns of the primary side wirings 4Aa and 4Ba and the secondary side wirings 4Ab and 4Bb of the pair of transformer parts 4A and 4B are formed point-symmetrically on the opposite side across the power supply line 3.

  Here, the point-symmetrical wiring pattern means that the lower or upper surface of the power supply line 3 has a point-symmetrical positional relationship with respect to a point P that is perpendicularly lowered from a point on the power supply line 3. Yes.

  Since the pair of transformer parts 4A and 4B are disposed at point symmetrical positions on the opposite side across the power supply line 3, magnetic flux induced by the excitation current of the power supply line 3 is applied in the same direction.

  In FIG. 7, since the wiring patterns of the pair of transformer parts 4A and 4B are point-symmetric with respect to the power supply line 3, the direction of the current generated in the wiring pattern by the magnetic flux applied in the same direction is two transformer parts 4A and 4A. The currents induced in the transformer unit 4A and the transformer unit 4B by the excitation current Ix of the power supply line 3 cancel each other.

(Third configuration of superconducting transformer)
A third configuration of the superconducting transformer will be described with reference to FIG. FIG. 8 is a schematic diagram for explaining the arrangement of the transformer part of the third configuration and the wiring pattern of the transformer part, and FIGS. 8A, 8B, and 8C are different viewpoints. The state seen from. FIG. 8C shows a state viewed from above.

  In FIG. 8, as in the first configuration, the adiabatic quantum flux parametron circuit 1 includes a power line 3, a superconducting quantum interference device (SQUID) 2 disposed along the power line 3, and a superconducting transformer 4. The superconducting quantum interference device (SQUID) 2 includes two Josephson junctions 2a and 2b with the central node 2c sandwiched between the superconducting rings 2d, and superconducting the output of the superconducting quantum interference device (SQUID) 2. Output from the transformer 4.

  In the superconducting transformer 4 of the third configuration example, a pair of transformer parts 4A and 4B are arranged in the same position on the same side with respect to the direction of the power supply line 3 with the power supply line 3 interposed therebetween. The wiring patterns of the primary side wirings 4Aa and 4Ba and the secondary side wirings 4Ab and 4Bb of the pair of transformer parts 4A and 4B are arranged so as to be horizontally reversed with respect to the plane including the power supply line 3. Although the ground is not shown in FIG. 8, the ground is provided below the transformer unit 4A provided below the power supply line 3 and above the transformer unit 4B provided above.

  Since the pair of transformer parts 4A and 4B are arranged in the same position in the direction of the power supply line 3 on the same side across the power supply line 3, the magnetic flux induced by the excitation current of the power supply line 3 is in the opposite direction. Become.

  In addition, since the wiring patterns of the pair of transformer parts 4A and 4B are in a horizontally reversed relationship with respect to the plane including the power supply line 3, the directions of currents generated in the wiring pattern by the magnetic flux induced in the reverse direction are opposite to each other. In the coupling portion at the input end of the primary side wiring and the coupling portion at the output end of the secondary side wiring, currents are input in opposite directions to cancel each other.

[Configuration of Superconducting Logic Device Using Adiabatic Quantum Flux Parametron Circuit of Present Invention]
The adiabatic quantum flux parametron circuit can perform a logical operation by making "1" and "0" correspond to the current direction, and depending on the output state of the output signal with respect to the input signal, the buffer, NOT, constant, and branch ( A superconducting logic element having each branching logic function can be configured.

  The superconducting logic element of the buffer outputs an output signal whose current direction is the same as the input signal, and the superconducting logic element of the NOT outputs an output signal whose current direction is opposite to the input signal, and is a constant superconducting logic element Always outputs a constant output signal regardless of the input signal. In the following, superconducting logic elements that perform the logical functions of buffer, NOT, constant, and branch will be described using the names of the buffer logic element, NOT logic element, constant logic element, and branch logic element, respectively.

(Buffer logic element)
The buffer logic element is a superconducting logic element having a buffer function, and an input signal is input to the central node of the superconducting quantum interference element (SQUID) included in the adiabatic quantum flux parametron circuit, and the secondary side wiring of the superconducting transformer In the configuration in which the output signal is output from the output terminal, the wiring pattern of the transformer part of the superconducting transformer is set so that the current direction of the output current output from the output terminal of the secondary wiring is the current of the input current input to the input terminal. The direction is the same as the direction.

  Since the configuration of the buffer logic element has been described with reference to FIGS. 2 to 8, the NOT logic element, the constant logic element, and the branch logic element will be described below with reference to FIGS. 9, 10, and 11. To do.

(NOT logic element)
The NOT logic element 11 inputs an input signal to the central node of the superconducting quantum interference element (SQUID) included in the adiabatic quantum flux parametron circuit, and changes the wiring pattern of the pair of transformer parts of the superconducting transformer to the secondary wiring. The current direction of the output current output from the output terminal is configured to be opposite to the current direction of the input current input to the input terminal. FIG. 9 is a diagram for explaining a configuration example of a NOT logic element.

  FIG. 9A shows a state in which the primary side wiring 4a (4Aa, 4Ba) and the secondary side wiring 4b (4Ab, 4Bb) are stacked, and FIG. 9B shows the secondary side for explaining the configuration. The wiring 4b (4Ab, 4Bb) is shown separately from the primary wiring 4a (4Aa, 4Ba).

  In FIG. 9, a superconducting quantum interference device (SQUID) 2 forms a superconducting ring 2d by grounding the ends of Josephson junctions 2a and 2b.

  In FIG. 9B, in the primary side wirings 4a and 4b constituting the superconducting transformer 4, the primary side wiring 4Aa and the primary side wiring 4Ba constituting the primary side wiring 4a are symmetrical in the direction of the power supply line 3. Further, the secondary side wiring 4Ab and the secondary side wiring 4Bb constituting the secondary side wiring 4b are also symmetrical with respect to a straight line orthogonal to the power supply line 3.

  In the primary side wirings 4 a and 4 b of the superconducting transformer constituting the NOT logic element 11, the primary side wiring 4 Aa and the primary side wiring 4 Ba constituting the primary side wiring 4 a are currents induced by magnetic coupling with the power supply line 3. The portion IA (indicated by a broken line in the figure) is in the opposite direction to the coupling portion Q of each wiring. In addition, regarding the secondary side wiring 4Ab and the secondary side wiring 4Bb constituting the secondary side wiring 4b, the current component IB (indicated by a broken line in the figure) induced by the magnetic coupling with the power source line 3 is shown for each wiring. Are opposite to each other.

  On the other hand, in the primary side wiring 4a, the primary current Iq by the output of the superconducting quantum interference element (SQUID) 102 is divided into two at the coupling portion Q, and the current component IC (shown by the solid line in the figure) is divided into the primary side wiring 4Aa and the primary side. It flows to the wiring 4Ba. Further, in the secondary side wiring 4Ab and the secondary side wiring 4Bb constituting the secondary side wiring 4b, a current component ID flows due to mutual magnetic coupling between the primary side wiring 4Aa and the primary side wiring 4Ba. The current ID is merged at the coupling portion R of the secondary side wiring 4Ab and the secondary side wiring 4Bb, and an output signal Iout is output.

  Since the pair of transformer parts 4A and 4B are arranged in parallel along the direction of the power supply line 3 on the same side with respect to the power supply line 3, a magnetic flux in the same direction is induced by the excitation current of the power supply line 3. On the other hand, since the wiring patterns of the pair of transformer parts 4A and 4B are symmetrical with respect to the direction of the power supply line 3, the direction of the current generated in the wiring pattern by the magnetic flux induced in the same direction is at the connection part of each wiring. On the other hand, they are opposite to each other and cancel each other.

  The spiral wiring pattern forming the secondary wiring 4b is set so that the current direction is opposite to the wiring pattern of the secondary wiring of the superconducting logic element constituting the buffer shown in FIGS. To do. By using this wiring pattern, the NOT logic element 11 having a NOT function is configured with the current direction of the output signal being opposite to the current direction of the input signal.

(Constant logic element)
The constant logic element 12 is a superconducting logic element that constitutes a buffer, and the layout of the superconducting quantum interference element (SQUID) included in the adiabatic quantum magnetic flux parametron circuit is asymmetric with respect to the central node, and is input to the central node. No end is provided and the input signal is not input. FIG. 10 is a diagram for explaining a configuration example.

  FIG. 10A shows a state in which the primary side wiring 4a (4Aa, 4Ba) and the secondary side wiring 4b (4Ab, 4Bb) are stacked, and FIG. 10B shows the secondary side for explaining the configuration. The wiring 4b (4Ab, 4Bb) is shown separately from the primary wiring 4a (4Aa, 4Ba).

  In FIG. 10, the superconducting quantum interference device (SQUID) 2 is not provided with an input end provided in the buffer configuration for the superconducting ring 2d formed by grounding the ends of the Josephson junctions 2a and 2b. Do not input signals.

  Superconducting quantum interference device (SQUID) 2 has an asymmetric layout with respect to center node 2c. The superconducting quantum interference device (SQUID) 2 has an asymmetric layout, so that when a pumping current is applied, it always becomes a specific logic state and has a constant output.

  The asymmetric layout can take several forms. In one form, the Josephson junctions 2a and 2b have different Josephson junction areas. FIG. 10 shows a configuration example in which the area of the Josephson junction 2a is larger than the area of the Josephson junction 2b.

  In another form, the length (line length) of the superconducting ring 2d sandwiching the center node 2c is made different. FIG. 10 shows a configuration example in which the length (line length) lb of one superconductive ring 2d is longer than the length (line length) la of the other superconductive ring 2d.

  Moreover, it can also be set as the form which provides shunt resistance. FIG. 10 shows an example in which a shunt resistor 2e is provided on the superconducting ring 2d on one Josephson junction side.

  The superconducting transformer of the constant logic element 11 can have the same configuration and operation as the buffer logic element described above. 10B, in the primary side wirings 4a and 4b constituting the superconducting transformer 4, the primary side wiring 4Aa and the primary side wiring 4Ba constituting the primary side wiring 4a are symmetrical in the direction of the power supply line 3. Further, the secondary side wiring 4Ab and the secondary side wiring 4Bb constituting the secondary side wiring 4b are also symmetrical with respect to a straight line orthogonal to the power supply line 3.

  Since the pair of transformer parts 4A and 4B are arranged in parallel along the direction of the power supply line 3 on the same side with respect to the power supply line 3, a magnetic flux in the same direction is induced by the excitation current of the power supply line 3. On the other hand, since the wiring pattern of the pair of transformer parts 4A and 4B is axisymmetric with respect to a straight line orthogonal to the power supply line 3, the direction of the current generated in the wiring pattern by the magnetic flux induced in the same direction is at the connection part of the wiring. On the other hand, the directions are opposite to each other, and the currents cancel out.

  In the primary-side wirings 4 a and 4 b of the superconducting transformer constituting the constant logic element 12, the primary-side wiring 4 Aa and the primary-side wiring 4 Ba constituting the primary-side wiring 4 a IA (shown by a broken line in the figure) is provided so as to be opposite to each other with respect to the coupling portion Q of each wiring. Also, for the secondary side wiring 4Ab and the secondary side wiring 4Bb constituting the secondary side wiring 4b, a current component IB (indicated by a broken line in the figure) induced by the magnetic coupling with the power supply line 3 It is provided to be opposite to each other with respect to the coupling portion R.

  On the other hand, in the primary side wiring 4a, the primary current Iq generated by the output of the superconducting quantum interference device (SQUID) 102 flows a current component IC (indicated by a solid line in the figure) divided in the coupling portion Q. Further, in the secondary side wiring 4Ab and the secondary side wiring 4Bb constituting the secondary side wiring 4b, a current component ID flows due to mutual magnetic coupling between the primary side wiring 4Aa and the primary side wiring 4Ba. The current ID is merged at the joint R between the secondary wiring 4Ab and the secondary wiring 4Bb and output as an output signal Iout.

  In addition to the form in which the layout of the superconducting quantum interference device (SQUID) is asymmetrical, a constant logic element can be configured by making the superconducting transformer asymmetrical. As an asymmetric configuration in the superconducting transformer, for example, a configuration in which the wiring length and the wiring width of the secondary wiring are made different can be adopted.

  The constant logic elements according to the above embodiments can be configured by at least one of them, and can have a constant function of outputting a constant output signal.

(Branch logic element)
The branch logic element 13 is a logic element that connects the superconducting logic elements, and has a function of dividing one input signal and outputting a plurality of output signals, or a function of outputting a plurality of input signals by majority logic. Provides the function of inputting the output signals of the buffer logic element, NOT logic element, and constant logic element and branching one input into a plurality of outputs, or the function of making a plurality of inputs from a plurality of superconducting logic elements one output by majority logic .

  The branch logic element 13 includes two wirings, one end of each of the wirings is used as an input end, the other end of each of the wirings is used as an output end, and both wirings are converted into both wirings by the excitation current of the power supply line. The induced magnetic flux directions are opposite to each other. With this configuration, the superconducting logic element is connected.

  FIG. 11 is a diagram for explaining a configuration example of a branch logic element. 11A shows a configuration example in which three input signals are output as one output signal by majority logic, and FIG. 11B shows a configuration example in which one input signal is branched into three output signals and output. Show.

  FIG. 11C shows a configuration example corresponding to the equivalent circuit of FIG. 12A, in which three input signals are inputted and one output signal is outputted by majority logic. The branch logic element 13 inputs three output signals of the three buffer logic elements 10a, 10b and 10c and outputs one output signal obtained by majority logic. FIG. 11C shows a configuration example of three buffer logic elements 10a, 10b, and 10c and a branch logic element 13 corresponding to FIG.

  In FIG. 11C, the branch logic element 13 includes a plurality of wiring portions (13-1, 13-2, 13-3) including two wirings 13A, 13B. The plurality of wiring sections (13-1, 13-2, 13-3) connect the ends of the two wirings 13A and 13B, respectively, and set one end as an input end 13a and the other end. The end portion is a coupling portion 13b. In the configuration example of FIG. 11C, the coupling portion 13b constitutes a common coupling portion among the three wiring portions (13-1, 13-2, 13-3) and is connected to the output end 13c.

  The configuration shown in FIG. 11 (c) shows a configuration example in which one output signal is output from three input signals, but three input signals are output by using the coupling portion 13b as an input end and the input end 13a as an output end. It can also be configured to divide the output into two.

  Note that FIG. 11 shows an example in which the number of wiring portions is three, but the number of wiring portions is not limited to three and may be any number. Also, the number of input ends and output ends is not limited to one, but can be any number within the number of wiring portions. For example, the ratio of the number of input terminals to output terminals is set to 3: 1 as illustrated, and 1: 3, 2: 1, 1: 2, 2: 3, 3: 2, 2: 5, 5: 2 etc. can be determined arbitrarily.

  In FIG. 11 (c), the wiring patterns of both wirings 13A and 13B are arranged with respect to the direction of magnetic flux induced by the power supply line 3 in the adiabatic quantum magnetic flux parametron circuit included in each superconducting logic element. It arrange | positions so that the electric current which flows into a direction may mutually become reverse with respect to the coupling | bond part 13b.

  The configuration shown in FIG. 11C is a configuration that has a function of making a plurality of inputs from a plurality of superconducting logic elements one output by majority logic, and the wiring patterns of the wirings 13A and 13B are symmetrical with respect to the center line. Thus, the current directions are opposite to each other. With this wiring pattern, the currents induced by the magnetic flux from the power supply line are canceled out in the opposite direction with respect to the current coupling portion. In FIG. 11C, the wirings 13A and 13B are bent so as to be opposite to each other to form a wiring pattern. However, any wiring pattern may be used as long as the current direction is opposite to the coupling portion 13b. It is good.

  The two wires have the current direction of both wires induced by the current of the power supply line opposite to the connection portion of the two wires, and the current induced in both wires by the current of the power supply line is the current connection portion. Against each other.

  In addition, by making the wiring lengths of the plurality of wiring portions equal, the inductances of the wiring portions in the branch logic element can be matched, and the magnitudes of the signal currents flowing through the wiring portions can be made uniform. Majority logic is possible by matching the signal levels from each element.

  The superconducting logic element of the present invention can constitute various logic circuits by combining the buffer logic element 10, NOT logic element 11, constant logic element 12, and branch logic element 13 described above. FIG. 12 is a diagram for explaining a configuration example of a logic circuit using the superconducting logic element of the present invention.

FIG. 12A is a diagram for explaining a configuration example of the majority logic circuit (MAJ) 21. The majority logic circuit (MAJ) can be configured by connecting the output terminals of the plurality of buffer logic elements 10 to the input terminals of the branch logic elements 13. The logic state of the output terminal x of the majority logic circuit (MAJ) 21 is represented by the sum of the output currents of the buffer logic elements 10. When the logic states of the input terminals of the buffer logic element 10 are a, b, and c, the logic state of the output terminal x of the majority logic circuit (MAJ) 21 is expressed by the following equation.
x = MAJ (a, b, c) = ab + bc + ca

FIG. 12B is a diagram for explaining a configuration example of the NAND logic circuit 22. The NAND logic circuit 22 can be configured by connecting the output terminals of two buffer logic elements 10 and the output terminal of one constant logic element 12 to the input terminal of the branch logic element 13. The logic state of the output terminal x of the NAND logic circuit 22 is represented by the sum of the output currents of the two buffer logic elements 10 and the constant logic element 12. When the logic states of the input ends of the two buffer logic elements 10 are a and b, the logic state of the output end x of the NAND logic circuit 22 is expressed by the following expression.
x = MAJ (a *, 1, c *) = (ab) *
Note that “*” represents sign inversion.

FIG. 12C is a diagram for explaining a configuration example of the split (SPL) logic circuit 23. The division logic circuit 23 can be configured by connecting the output terminal of the buffer logic element 10 to the input terminal of the branch logic element 13. The logic states of the output terminals x, y, and z of the divided logic circuit 23 are expressed by the following equations when the logic state of the input terminal of the buffer logic element 10 is a.
x = y = z = a

  The present invention is not limited to the above embodiments. Various modifications can be made based on the spirit of the present invention, and these are not excluded from the scope of the present invention.

  The adiabatic quantum flux parametron circuit and superconducting logic element of the present invention can be applied to the field of superconducting integrated circuits.

1 adiabatic quantum flux parametron circuit 1a input terminal 1b output terminal 2 superconducting quantum interference device 2a, 2b Josephson junction 2c central node 2d superconducting ring 2e shunt resistor 3 power line 4 superconducting transformer 4in input terminal 4out output terminal 4A, 4B Transformer 4a, 4Aa, 4Ba Primary side wiring 4b, 4Ab, 4Bb Secondary side wiring 10 Buffer logic element 11 NOT logic element 12 Constant logic element 13 Branch logic element 13A, 13B Wiring 13a Input terminal 13b Coupling part 13c Output terminal 21 Majority logic circuit (MAJ)
22 logic circuit 23 division logic circuit 101 adiabatic quantum flux parametron circuit 102 superconducting quantum interference device 102a, 102b Josephson junction 102c central node 102d superconducting ring 103 power supply line 104 superconducting transformer 104a primary side wiring 104b secondary side wiring 104c Output 110 Superconducting shield

Claims (14)

A superconducting quantum interference device (SQUID) having two Josephson junctions sandwiching a central node in a superconducting ring, a power line for inducing magnetic flux in the superconducting quantum interference device, and a current of the superconducting quantum interference device An adiabatic quantum magnetic flux parametron circuit with a superconducting transformer for output,
The superconducting transformer includes a pair of transformer parts each having a primary side wiring and a secondary side wiring,
The pair of transformer parts are:
The pair of wirings of the primary side wiring connects both input ends of the pair of wirings to the central node of the superconducting quantum interference element and leads to a pair of wirings of the primary side wiring by magnetic coupling with the power supply line. The directions of the currents to be made are opposite to each other with respect to the input ends of the pair of wires,
The pair of wires of the secondary side wire connect both output ends of the pair of wires to the output end of the adiabatic quantum magnetic flux parametron circuit , and a pair of secondary side wires by magnetic coupling with the power supply line. An adiabatic quantum flux parametron circuit characterized in that the directions of currents induced in the wirings are opposite to each other with respect to the output ends of the pair of wirings. In the superconducting transformer,
The arrangement of the pair of transformer parts is parallel to the power supply line along the direction of the power supply line on the same side, and
The wiring pattern of the primary side wiring and the secondary side wiring of the pair of transformer parts is opposite to the direction of magnetic flux induced by magnetic coupling with the power supply line. Adiabatic quantum flux parametron circuit as described in 1. In the superconducting transformer,
The arrangement of the pair of transformer parts is parallel to the power supply line along the direction of the power supply line on the same side, and
2. The adiabatic quantum flux parametron according to claim 1, wherein the wiring patterns of the primary side wiring and the secondary side wiring of the pair of transformer parts are axisymmetric with respect to a straight line orthogonal to the power supply line. circuit. In the superconducting transformer,
2. The arrangement of the pair of transformer parts and the wiring patterns of the primary side wiring and the secondary side wiring of the pair of transformer parts are point-symmetric on the opposite side across the power supply line. Adiabatic quantum flux parametron circuit as described in 1. In the superconducting transformer,
The arrangement of the pair of transformer parts is formed by laminating at the same position with respect to the direction of the power supply line on the same side across the power supply line, and
2. The adiabatic quantum flux parametron circuit according to claim 1, wherein the wiring patterns of the pair of transformer parts are symmetrical with respect to a plane including the power supply line.   6. The adiabatic quantum flux parametron circuit according to claim 1, wherein an inductance of the secondary wiring is larger than an inductance of the primary wiring. In the opposing arrangement of the primary side wiring and the secondary side wiring,
The wiring length of the secondary side wiring is long than the wiring length of the primary-side wiring, the smaller than the line width of the line width of the secondary side wiring the primary side wiring, or the wiring of the secondary wire The heat insulation type according to any one of claims 1 to 5, wherein a length of the primary side wiring is long and a width of the secondary side wiring is smaller than a width of the primary side wiring. Quantum magnetic flux parametron circuit. In the adiabatic quantum flux parametron circuit according to any one of claims 1 to 7,
An input line having an input end is connected to the central node;
The wiring pattern of the pair of transformer parts is a pattern in which the current direction of the output terminal of the secondary wiring is the current direction of the input terminal,
A superconducting logic element comprising a buffer function logic element for outputting an output current in the same direction as the input current input from the input terminal from the output terminal of the secondary wiring . In the adiabatic quantum flux parametron circuit according to any one of claims 1 to 7,
An input line having an input end is connected to the central node;
The wiring pattern of the pair of transformer parts is a pattern in which the current direction of the output end of the secondary side wiring is a direction opposite to the current direction of the input end,
And characterized in that it constitutes a logic element NOT function of outputting the output current of the current direction opposite direction of the input current inputted from the input end from the output end of the secondary wire, the superconducting logic elements. In the adiabatic quantum flux parametron circuit according to any one of claims 1 to 7,
An input line is disconnected from the central node,
The superconducting quantum interference device (SQUID) is configured to be asymmetric with respect to a central node, and a constant-function logic device that constantly outputs current from the output terminal of the secondary wiring when excited by the power supply line. Superconducting logic device characterized by The asymmetric configuration with respect to the central node of the superconducting quantum interference device (SQUID) is:
Configuration with two Josephson junctions having different areas, characterized in that at least one of configuration comprising a superconducting ring having different line lengths sandwiching the heart nodes in及beauty, claim 10 Superconducting logic element. In the adiabatic quantum flux parametron circuit according to any one of claims 1 to 7,
The superconducting transformer, and an asymmetrical configuration having different at least one of the wiring length及beauty wiring width of the pair of the transformer of the secondary side wiring, logical constant function of outputting a current at all times upon excitation by said power line A superconducting logic element comprising an element. A superconducting logic element for connecting the superconducting logic elements according to any one of claims 8 to 12,
It has a plurality of wiring parts consisting of two wires,
The wiring portion connects one of the plurality of wiring portions,
In each wiring section, the two wirings connect each end, one of the connection ends as the input end and the other as the output end,
A superconducting logic element characterized in that the direction of the current of both wirings induced by the current of the power supply line is opposite to the joint of the two wirings.   The superconducting logic device according to claim 13, wherein the wiring lengths of the plurality of wiring portions are equal.