JPH03291017A - Polarity switching type josephson driving circuit - Google Patents

Abstract

PURPOSE:To reduce the circuit area, to simplify the layout of the circuit and to attain high circuit integration by forming a polarity switching type Josephson driving circuit with only a direct coupling type Josephson gate circuit. CONSTITUTION:Josephson junctions J11, J12 of a 1st direct coupling type Josephson gate circuit G11 in a 1st driving voltage generating circuit 1 are switched from the superconducting state into the voltage state at a time T1, a bias current is supplied to a junction J13 of a direct coupling type Josephson gate circuit G12 through a resistor R13 (in this case, R110<R13), then the junctions J13, J14 are switched from the superconducting state into the voltage state (in this case, R120<R13) at a time T2, a bias current is injected to a line to be driven 3 and supplied to ground through a junction J23 of a driving voltage generating circuit 2. In such a case, a signal inputted from a terminal S1A flows to ground through the resistors R12, R120 when the junctions J12, J14 in the circuit 1 are switched into the voltage state so as to separate the bias current from the input and output signal.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a superconducting integrated circuit using a Josephson device, and more particularly to driven lines such as word lines and human lines of a superconducting memory integrated circuit. The present invention relates to a polarity switching type jikagasenon drive circuit that can inject a current into the circuit and arbitrarily reverse the direction of the current.

[Traditional techniques]

Figure 3 shows an equivalent circuit diagram for explaining the conventionally known polarity switching type Josephson drive circuit (Showa 6).
The conventional technology will be explained with reference to FIG. 3 (IEICE Spring National Conference).

As shown in Fig. 3, the conventional polarity switching type Josephson drive circuit consists of four magnetic field coupling type Josephson non-gate circuits Gl.
, G2,03. (j4, three resistors 31, R2, R, and the word structure of the memory cell array 4 or a driven line such as a bit line) are connected to the bias input terminal B in the two circuits.
1 to via 2, the signal input terminal 81
When a signal is input to the magnetic field coupling type Jimi Sefson gate circuit (1, G3 switches from the superconducting state to the voltage state and the bias current is injected into the driven line 3. The bias current tlIL flowing through the covered Jk11 line 3 flows into the ground through the magnetic field coupling type output circuit G4.By the above operation, an output current can be generated directly in the clockwise direction on the driven line.On the other hand, the bias from the input terminal B2 of ) When a signal is input to the signal input terminal S2 while supplying current, a magnetic field integration type Josephson gate circuit G2,
G4 switches from the superconducting state to the voltage state and a bias current is injected into the driven line (return line 5).

The bias current flowing through the driven line flows into the ground through the magnetic field coupling type Girosefsoncate circuit G3. By the above operation, it is possible to generate an output current in the long-duration 9 directions in the driven line.

As described above, it is possible to realize a polarity-switching type Jirosefson drive circuit that can inject a current into a driven line and arbitrarily reverse the direction of the current using the conventional technology.

[Problem to be solved by the invention]

In the conventional technology, since a magnetically coupled Josephson gate circuit (two-junction 5QUID gate) is used, a region for magnetic coupling between the control circuit and the 8QUID loop for injecting the input signal is obtained. Therefore, there is a problem in that the area of the element is large and large-scale integration is difficult.

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the problems of the conventional polarity switching type Josephson drive circuit and to provide a polarity switching type dilcefnon drive circuit which allows miniaturization of the circuit.

[Means to solve the problem]

According to the present invention, the bias input terminal of the first direct coupling type Josephson gate circuit is connected to the bias input terminal, and the second bias input terminal is connected to the output terminal of the first direct coupling type Josephson gate circuit via a load resistor. The bias input terminal of the direct coupling type Josephsongate circuit is connected to the bias input terminal of the direct coupling type Josephson gate circuit, and the signal input terminal of the first direct coupling type Josephson gate circuit is connected to the signal input terminal via a first input resistor, and The signal input terminal of the second direct coupling type Josephsongate circuit is connected to the signal input terminal through a second input resistor, and the output terminal of the second direct coupling type Josephsongate circuit is connected to the output terminal. 10 drive voltage generation circuits connected to each other, a second drive voltage generation circuit having the same circuit configuration as the first drive voltage generation circuit, and the first and second drive voltage generation circuits. A polarity-switchable Josephson drive circuit is obtained, which includes a driven line connected between the output terminals.

〔Example〕

FIG. 1 is an equivalent circuit diagram for explaining one embodiment of the present invention.

The embodiment shown in FIG. 1 includes two llAl#J voltage generating circuits (1, 2), a driven line 3 consisting of a memory cell array, a driven ll1AIJJ line consisting of a return line 15 of a memory cell array 4, The driven line 3 is connected to the output terminal 01A of the first drive voltage generation circuit IA and one end of the resistance ratio, and the output of the two second drive voltage generation circuits is connected to the other end of the resistor R. It has a configuration in which a return line 5, which is a driven line, is connected to the end 02A. Since the first and second drive voltage generation circuits have the same circuit configuration, the first drive voltage generation circuit will be described below as an example.

The first drive voltage generation circuit 1 includes a first direct coupling type non-gate circuit Gll consisting of two Josephson junctions Jll, J12 and a resistance ratio of 110, and two di-1cefun junctions J13. A second direct coupling type Josephson gate circuit 012 consisting of J14 and a resistance ratio of 120, a first input resistance kL11, a second input resistance R12, and a load resistance R1.
It consists of 3. A bias input terminal B12 of a second direct coupling type Josephson gate circuit G12 is connected to the output terminal 011 of the first direct coupling type Josephson gate circuit G11 via a load resistor R13. Cefnon gate circuit (first at the signal input terminal 811 of jll,
Second input resistance ratio 11. A signal input terminal 812 of a second direct-coupled Josephson gate circuit G12 is connected through the line 12. Here, it is assumed that the first input resistance R11 is smaller than the second input resistance R12.

Since the polarity switching type Josephson drive circuit of this embodiment is formed only with a direct coupling type Josephson gate circuit, the circuit area can be significantly reduced compared to the magnetic field coupling type Josephson gate circuit shown in the conventional technology. can be reduced to

The operating principle of the polarity switching type Josephson drive circuit of this embodiment is as follows.

When a bias current is supplied from the bias input terminal BIA and an input signal current with a rising time T as shown in FIG. resistance all.

The input terminals S11.81 of the first and second directly coupled Josephson gate circuits Gll and G12 are divided into a ratio of approximately 12.
It flows to 2. Now, set the ratio of input resistance R11゜R12 to 1
When the pair is 2, the current value flowing to the input terminal of the gate circuit G11°G12 becomes -1N, -\IN, as shown by the broken line in Figure 2 (IN is the terminal SI
In Fig. 2, the IC is a direct-coupled Josephsongate circuit (jll,
G12 is the critical current value for switching from the superconducting state to the voltage state. Therefore, in the first drive voltage generation circuit 1, the Josephson junctions J11 and J12 of the direct-coupled Josephson gate circuit Gll switch from the superconducting state to the voltage state at time T1, and the bias current is transferred to the direct-coupled type through the resistor R13. The flow flows to Josephson junction J13 of Josephson gate circuit G12 (however, R110<R13), and then at time T2 Josephson junctions J13 and J1
4 switches from the superconducting state to the voltage state. However, R1
20<R), a bias current is injected into the driven line 3. The bias current flowing through the driven line 3 flows into the ground through the Josephson junction J23 of the drive voltage generating circuit 2. At this time, the signal input from terminal 81A is
In the drive voltage generation circuit 1, Josephson junction J12
When J14 reaches the voltage state, it flows to ground through resistor R120, so that the input and output are separated from the bias current. The above operation allows the output current i to be generated in the clockwise direction on the driven line.

On the other hand, when a bias current is supplied from the bias input terminal B2A and an input signal current with a rising time T shown in FIG. The Josephson junctions J21 and J22 of the coupled Josephson Kate circuit G21 are at time T.
1, the bias current flows through the resistor R23 to the Josephson junction J23 of the direct-coupled Josephson gate circuit G22, and then at time T2, the Josephson junction J23~J24 switches from the superconducting state to the voltage state. A bias current Fi is injected into the driven line 5. The bias current flowing through the driven line Kfi flows through the Josephson junction J13 of the drive voltage generating circuit 1 to ground. At this time, the signal input from the terminal S2A is sent to the Josephson junction J22. When J24 switches to the voltage state, resistor L22. Since it flows to ground through R220, the input and output are separated from the bias current. By the above operation, an output current can be generated in the driven line in the counterclockwise direction. Here, the input resistances are 11 and 21. R12
As mentioned above, the value of R22 is determined by the direct coupling type Josephson gate circuit G11゜G21 switching to the voltage state and transmitting its output current to the direct coupling type Josephson gate circuit 01.
2. After inputting to the bias end of G22, the input signal causes a direct coupling type Josephson gate circuit G12. It is necessary to decide for G22 to switch to the voltage state.

In order to operate the polarity switching type Josephson drive circuit of this embodiment with a wide operation margin, circuit constants may be determined as follows, for example.

11:I3. I2:I4. II/2<I2<11R11
(=R21)<R12 (=R22) where IO, I2
．． I3. I4 is a Josephson junction Jll and J21. J1
2 and J22. J13 and J23. These are the superconducting critical current values of J14 and J24.

As described above, according to the present embodiment, it is possible to realize a pole phase switching type Josephson drive circuit in which the area of the circuit is reduced and high integration is possible.

In this embodiment, the resistor 5 is inserted into the driven line, but the same effect can be obtained by using a reset gate composed of a Josephson junction instead.

In addition, in one embodiment, the
J12, . . . have a plurality of these, for example 41! Those connected in series may also be used.

The operating time of the circuit can be evaluated by LI/V, where the inductance of the driven line consisting of the memory cell array is V and the drive current (output current) is V and I is the drive current (output current).

The drive voltage V is the voltage generated when the Josephson junction switches to a voltage state. Therefore, by connecting a plurality of Josephson junctions in series, it is possible to generate a driving voltage several times higher than that in one embodiment, and to shorten the operating time.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to realize a polarity switching type Josephson drive circuit that is capable of miniaturizing the circuit and operating at high speed.

[Brief explanation of drawings]

FIG. 1 is an equivalent circuit diagram illustrating an embodiment of the polarity switching type Joseph Non drive circuit according to the present invention, and FIG.
A schematic diagram showing an input current waveform for explaining the operating principle of the polarity switching type zicocefnon drive circuit according to the present invention.
FIG. 1 is an equivalent circuit diagram for explaining a polarity switching type Josephson drive circuit according to the prior art. DESCRIPTION OF SYMBOLS 1...First drive voltage generation circuit, 2...Second drive voltage generation circuit, 3...IIA flow line, 4...Memory cell array, 5...Return line, BIA, Bl
l, B12, B2A, B21. B22--bias input terminal, 01-G4...magnetic field coupling type Josephson gate circuit, Gll...first direct coupling type Josephson gate circuit of the first drive voltage generation circuit, G12...th A second direct-coupled Josephson gate circuit of the first drive voltage generation circuit, G21...a first direct-coupling Josephson gate circuit of the second drive voltage generation circuit, G22...second drive Second Directly Coupled Sefson Gate Circuit of Voltage Generating Circuit, Jll, J12. J13゜J14. J21
．． J22. J23. J24...Josephson junction, M
1~MN...Memory cell, 011,012°(1)I
A, 021,022. U2A-ffi power! , R11-・
・First input resistance of 1, 1 (12...1cD second input resistance, R21...2 first input resistance, about 22...
・Second input resistance of 2, 81.81 people, 52,82A・
...Signal input terminal.

Claims (1)

[Claims] A bias input terminal of a first direct-coupled Josephson gate circuit is connected to the bias input terminal, and a second direct-coupled Josephson gate circuit is connected to the output terminal of the first direct-coupled Josephson gate circuit via a load resistor. A bias input terminal of the gate circuit is connected, a signal input terminal of the first direct coupling type Josephson gate circuit is connected to the signal input terminal via a first input resistor, and a second input terminal is connected to the signal input terminal. A first drive voltage, in which the signal input terminal of the second direct-coupled Josephson gate circuit is connected to the output terminal of the second direct-coupled Josephson gate circuit, and the output terminal of the second direct-coupled Josephson gate circuit is connected to the output terminal. a generating circuit, a second driving voltage generating circuit having the same circuit configuration as the first driving voltage generating circuit, and a driven line connected between the output terminals of the first and second driving voltage generating circuits. A polarity switching type Josephson drive circuit comprising: