JP2006331249A - Quantum program conversion apparatus, its method and program, and recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To execute the programming of a quantum computer without considering the hardware of the quantum computer. <P>SOLUTION: Class library in which class library identification information corresponding to a quantum system of the quantum computer, quantum processing description information and quantum gate information are related to each other is previously stored in a class library storage part 140. Then an analysis part 161 extracts class library specification information for specifying the class library identification information and the quantum processing description information from a quantum program. Then a retrieval part 162 extracts the quantum gate information corresponding to the class library specification information and the quantum processing description information which are extracted by the analysis part 161 from the class library. Then a quantum circuit generation part 163 generates a quantum circuit by using the quantum gate information extracted by the retrieval part 162 and outputs quantum circuit information indicating the quantum circuit. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a quantum program conversion apparatus, a method thereof, a program thereof, and a recording medium for converting a source code describing processing contents by a quantum computer into a quantum circuit.

[Quantum computer]
Computers called “quantum computers” have been proposed that can solve problems much faster than current computers for specific problems such as factorization and search. A quantum computer is a computer that uses “qubits” as a calculation unit instead of bits of a calculation unit used in ordinary computers. When qubits are used, bit string superposition can be expressed. The high speed of a quantum computer can be obtained by quantum parallel computation using superposition.

In quantum mechanics theory, the quantum state created by n qubits is represented by a 2 ^n- dimensional Hilbert space vector, the quantum operation is represented by a 2 ⁿ × 2 ⁿ unitary matrix, and the quantum state is experimentally measured. Is expressed by a projection operator. In the quantum computer, the input data is expressed by the quantum state of the qubit string, and the calculation is performed by manipulating the input data and performing the observation at the end. When this process is expressed in terms of quantum mechanics theory, a vector in the Hilbert space that represents the initial state is transformed with a unitary matrix that represents the quantum operation, and a projection operator is applied to the obtained vector to obtain it. Is equivalent to the output of the quantum computer.

[Universal Gate]
In general, it is difficult to physically realize an arbitrarily given unitary matrix. Therefore, a combination of basic operations capable of approximating an arbitrary unitary matrix if prepared in combination is prepared, and a desired unitary matrix is realized by combining the basic operations. A combination of basic operations that can approximate any unitary matrix by combining them is called a universal gate. These basic operations are often expressed by logic gate-like symbols and are also called quantum gates. In addition, a circuit in which quantum gates are arranged like a logic circuit is called a quantum circuit.

The most famous universal gate is a set of 1-qubit rotation operation and CNOT (see Non-Patent Document 1, for example). The combination of the 1-qubit rotation operation and the control rotation gate is also a universal gate. With these universal gates, any unitary matrix can be accurately represented (not approximate) by a quantum gate. However, in order to represent an arbitrary unitary matrix using these universal gates, an infinite number of quantum gates must be used.
On the other hand, there is a universal gate composed of a limited number of quantum gates. A well-known example is a set of Hadamard gate, phase gate, CNOT, and π / 8 gate. This is a finite subset of universal gates consisting of one qubit rotation operation and CNOT. In this universal gate, the unitary matrix cannot be expressed accurately but can be approximated. Therefore, quantum computation can be executed using these four quantum gates. Further, a set of Hadamard gates, phase gates, CNOT gates, and tori gates is an example in which a limited number of units become universal (see, for example, Non-Patent Document 2).

[Physical constraints required for Universal Gate]
When the universal gate as described above is implemented in a quantum computer, there are predetermined physical constraints for each quantum system. Research is also underway to construct an optimal quantum circuit based on such physical constraints.
For example, physical constraints that are likely to be required for universal gates in most quantum systems include the interaction between adjacent qubits. Since the entangled state must be controlled in the operation of the quantum computer, a quantum gate of 2 qubits or more such as CNOT is essential. In the universal gate model of 1 qubit rotation operation and CNOT, CNOT operation between 2 qubits that are far apart is permitted. However, in most quantum systems except ion traps, it is difficult to interact with qubits that are far away. On the other hand, Patent Document 1 discloses a method for constructing an efficient quantum circuit in a quantum system in which only an interaction between adjacent qubits can be used.

  In addition, since the exchange operation is naturally derived from Heisenberg-Hamiltonian describing the behavior of the spin system, it is natural to place such constraints on the model when creating a quantum computer with a spin system. Furthermore, it is known that performing quantum computations only by exchange operations is effective in reducing the influence of external noise, and is a powerful model for quantum computers made with spin systems. . Non-Patent Document 3 discloses a method for constructing an efficient quantum circuit in a case where such a restriction that only an exchange operation between adjacent qubits is allowed is imposed.

Thus, due to physical restrictions on each quantum system, the optimal universal gate for expressing the unitary matrix often differs depending on the quantum system. For example, depending on the quantum system, a physical configuration may be more easily realized by an operation other than CNOT. Since the quantum circuit is like an assembler program in a current computer, even if the same unitary transformation is realized, if the universal gate to be used is different, the quantum circuit that approximates it is completely different.
[Quantum programs and quantum compilers]
In this way, various universal gates can be assumed depending on the quantum system, so it is unrealistic for an engineer who designs a quantum program (a code describing processing contents by a quantum computer) to directly design a quantum circuit. . In order to design a quantum algorithm, it is natural that a quantum language that is easier for humans to handle and a quantum compiler that converts it into a quantum circuit are desired.

The simplest quantum language is an existing program with unitary matrix and observational descriptions. The existing program portion is executed by the existing classical computer, and the unitary matrix and the observation portion are executed by the quantum computer by decomposing the unitary matrix into universal gates. A method of decomposing a given unitary matrix into a 1-qubit rotation operation and CNOT is disclosed in Non-Patent Documents 4 and 5, for example. Non-Patent Document 6 proposes a quantum programming language based on type theory.
A. Barenco, CH Bennett, R. Cleve, DP DiVincenzo, N. Margolus, P. Shor, P. Sleator, JA Smolin, H. Weinfurter, Elementary Gates for Quantum Computation, Physical Review A 52, 3457 (1995) MA Nielsen and IL Chuang, Quantum Computation and Quantum Information, Section 4.5, Cambridge University Press. Yasuno Kawano, Junji Kimura, Hiroshi Sekigawa, “On Quantum Gates in the Decoherence-free subspace”, Science Technique, COMP2004-23, June 2004 RR Tucci, A Rudimentary Quantum Compiler (2nd edition), [online], [Search May 20, 2005], Internet <http://arxiv.org/abs/quant-ph/9902062> RR Tucci, Qubiter Algorithm Modification, Expressing Unstructured Unitary Matrices with Fewer CNOTs), [online], [Search May 20, 2005], Internet <http://arxiv.org/abs/quant-ph/0411027> Peter Selinger, Towards a quantum programming language, Mathematical Structures in Computer Science 14 (4): 527-586, 2004. JP 2004-094885 A

Conventionally, however, it has been difficult to program a quantum computer without a wealth of knowledge about the hardware of the quantum computer.
That is, as described above, the optimal universal gate depends on the quantum system of the quantum computer. However, designers of quantum programs are not necessarily familiar with quantum computers even if they are familiar with programming. Therefore, for the spread of quantum computers, there has been a demand for an environment where programming can be performed without being aware of usable quantum gates.
The present invention has been made in view of these points, and by automatically converting a quantum language that is easy to handle by humans into an optimal quantum circuit corresponding to the quantum system of the quantum computer, the hardware of the quantum computer is provided. It is an object of the present invention to provide a technical idea that enables programming of a quantum computer without considering the above.

  In the present invention, in order to solve the above-mentioned problem, class library identification information corresponding to the quantum system of the quantum computer, quantum processing description information describing processing contents by the quantum computer, and the class library identification information are stored in the class library storage unit. A class library in which quantum gate information indicating a quantum gate suitable for realizing the processing content indicated by the quantum processing description information is stored in the quantum computer corresponding to the above is stored. When a quantum program is input, the analysis unit extracts class library designation information and quantum processing description information for designating class library identification information from the quantum program. Next, in the search unit, quantum gate information corresponding to the class library designation information and the quantum processing description information extracted by the analysis unit is extracted from the class library. Thereafter, the quantum circuit generation unit generates a quantum circuit using the quantum gate information extracted by the search unit, and outputs quantum circuit information indicating the quantum circuit.

Here, if class library designation information corresponding to a quantum computer that executes a quantum program is embedded in the quantum program, a quantum circuit suitable for the quantum computer is automatically generated.
Preferably, the class library storage unit stores class library identification information corresponding to a quantum system of the quantum computer, quantum processing description information describing processing contents by the quantum computer, and a quantum computer corresponding to the class library identification information. A class library associated with quantum gate information indicating a quantum gate suitable for realizing the processing content indicated by the quantum processing description information is stored, and the error correction library storage unit further stores a quantum system of the quantum computer. The error correction library associated with the error correction library identification information corresponding to the above, quantum gate information, and error correction quantum gate information obtained by converting the quantum gate information into a circuit configuration capable of error correction is stored. When a quantum program is input, the analysis unit, from the quantum program, class library designation information for designating class library identification information, error correction library designation information for designating error correction library identification information, quantum Process description information is extracted. Next, in the first search unit, quantum gate information corresponding to the class library designation information and the quantum processing description information extracted by the analysis unit is extracted from the class library. In the second search unit, error correction quantum gate information corresponding to the error correction library designation information extracted by the analysis unit and the quantum gate information extracted by the first search unit is extracted from the error correction library. The quantum circuit generation unit generates a quantum circuit using the error correction quantum gate information extracted by the second search unit, and outputs quantum circuit information indicating the quantum circuit.

  Here, if the class library specification information and error correction library specification information corresponding to the quantum computer that executes the quantum program is embedded in the quantum program, an error-correctable quantum circuit suitable for the quantum computer is automatically generated. Is done.

  In the present invention, since a quantum circuit suitable for a quantum computer is automatically generated from a quantum program, the quantum computer can be programmed without considering the hardware of the quantum computer.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[First Embodiment]
<Device configuration>
FIG. 1 is a block diagram illustrating the configuration of the quantum program conversion apparatus 100 according to the first embodiment.
As illustrated in this figure, the quantum program conversion apparatus 100 of this embodiment includes a control unit 110, an input unit 120, an output unit 130, a class library storage unit 140, a temporary memory 150, an analysis unit 161, a search unit 162, and a quantum circuit. It has a generation unit 163, a classical code generation unit 165, and a linker unit 166, and converts the input quantum program into quantum circuit information and outputs it. The analysis unit 161 includes a lexical analysis unit 161a, a syntax analysis unit 161b, and a semantic analysis unit 161c, and the temporary memory 150 includes regions 151 to 158. Further, description of the library used by the analysis unit 161 and the classical code generation unit 165 is omitted.

  Here, the quantum program conversion apparatus 100 of this example includes a CPU (Central Processing Unit) having a control unit, a calculation unit, a register, and the like, a main storage device such as a RAM (Random Access Memory) and a ROM (Read Only Memory), and a hard disk A predetermined program is read into a known Neumann computer having an auxiliary storage device such as a device and an input / output interface. Specifically, for example, the control unit 110, the analysis unit 161, the search unit 162, the quantum circuit generation unit 163, the classical code generation unit 165, and the linker unit 166 read a predetermined program into the CPU and execute it It is comprised by doing. The input unit 120 and the output unit 130 are input / output interfaces such as USB (Universal Serial Bus). Furthermore, the class library storage unit 140 and the temporary memory 150 are configured from, for example, a register, a cache memory, a RAM, a hard disk device, and the like.

<Data structure>
FIG. 2A is a conceptual diagram illustrating the state of the class libraries 200-1 to 200-n stored in the class library storage unit 140 illustrated in FIG.
As illustrated in FIG. 2A, the class library storage unit 140 stores a plurality of class libraries 200-1 to 200-n. Each of these class libraries 200-1 to 200-n is a quantum system (nuclear magnetic resonance (NMR) system, crystal lattice quantum system, ion trap system, linear optics) of a quantum computer in which a quantum circuit generated from a quantum program is mounted. The system is formed corresponding to a physical element whose operation principle is a phenomenon specific to quantum mechanics represented by an element system or the like.

FIG. 2B is a conceptual diagram illustrating the data configuration of the class library 200-1 in FIG.
As illustrated in FIG. 2B, the class library 200-1 includes class library identification information 210-1 corresponding to the quantum system of the quantum computer, and quantum processing description information 220-1 describing processing contents by the quantum computer. And quantum gate information 230-1 indicating a quantum gate suitable for realizing the processing content indicated by the quantum processing description information 220-1 in the quantum computer corresponding to the class library identification information 210-1. ing.

The class library identification information 210-1 in this example is information for identifying the class library 200-1, and “cstd1” is set in this example. The quantum processing description information 220-1 in this example includes CNOT (y.CNOT (x);), negative CNOT (inverts the target bit when the control bit is 0) (y.CNOT (! X); ), Hadamard transform (x.hadamard ();), S transform (xS ();), π / 8 gate (xT ();), control rotation (y.CR _k (x);), Toffoli (z. toffoli (x, y);) etc., and corresponds to the code extracted by the analysis unit 161 analyzing the quantum program. Further, the quantum gate information 230-1 is information indicating a quantum gate corresponding to each quantum processing description information 220-1. The quantum processing description information 220-1 may correspond to only a basic quantum gate (for example, CNOT), or a quantum gate (for example, a quantum Fourier transform, addition, etc.) that combines the basic quantum gates. The thing corresponding to may be included.

3 and 4 are diagrams illustrating the quantum gate indicated by the quantum processing description information 220-1. Here, FIGS. 3A to 3D respectively show CNOT (y.CNOT (x);), negative CNOT (y.CNOT (! X);), Hadamard transform (x.hadamard ();), FIG. 4A to FIG. 4C show a π / 8 gate (xT ();) and a control rotation (y.CR _k (x);). , Shows a quantum gate corresponding to Toffoli (z.toffoli (x, y);). Any quantum gate data representation method may be used. For example, it is represented by a set of “gate name. Control bit. Target bit. Rotation angle” (a null value is inserted at a position where no element exists). To do. In this example, the quantum gate information 1-1 corresponding to CNOT (y.CNOT (x);) is “quantum bit position corresponding to NOT.x.quantum bit position corresponding to y.null value”. . Further, when the quantum processing description information 220-1 is configured by a set of a plurality of basic quantum gates (for example, quantum Fourier transform, addition, etc.), a plurality of “gate name. Control bit. Target bit. Rotation angle”. May be arranged in time series to constitute the quantum processing description information 220-1.

FIG. 5A is a conceptual diagram illustrating the data configuration of the class library 200-2 in FIG.
The class library 200-2 is also configured by associating class library identification information 210-2, quantum processing description information 220-2, and quantum gate information 230-2. However, since it corresponds to a quantum computer of a quantum system different from the case of the class library 200-1, at least a part of the contents of the quantum gate information 230-2 is different from the class library 200-1.

FIG. 5B illustrates the contents of the quantum gate information 2-2 corresponding to negative CNOT (y.CNOT (! X);) of the class library 200-2. Here, as can be seen from comparison with FIG. 3B described above, in the class library 200-1 and the class library 200-2, the same quantum processing description information 220-1, 2 (negative CNOT (y.CNOT (! X );)) Are associated with different quantum gate information 230-1 and 230-2. This is because physically optimum quantum gate information is set in the corresponding quantum computers.
Other class libraries are also configured by associating class library identification information, quantum processing description information, and quantum gate information, but the contents of quantum gate information differ depending on each corresponding quantum computer.

<Quantum program>
FIG. 6 is a diagram illustrating a quantum program 300 according to the first embodiment.
As illustrated in this figure, the quantum program 300 includes a classic processing description information source code 301 which is a source code describing processing contents in a classical computer, and a class library designation information source for designating the class library identification information described above. The code 302 and the quantum processing description information source code 303 which is a source code describing the processing contents in the quantum computer are included. Note that the quantum processing description information source code 303 describes only the processing contents in the quantum computer, and does not describe specific information about the quantum circuit.

<Processing>
Next, quantum program conversion processing in the first embodiment will be described.
FIG. 7 is a flowchart for explaining the quantum program conversion processing according to the first embodiment. Hereinafter, the quantum program conversion process of this embodiment will be described with reference to this figure.
First, a quantum program is input in the input unit 120, and the input quantum program is temporarily stored in the area 151 of the temporary memory 150 (step S1). Next, in the analysis unit 161, a quantum program is read from the area 151 of the temporary memory 150, and class library designation information, quantum processing description information, and classical process description information for designating class library identification information are obtained from the quantum program. Extract (step S2). Specifically, for example, first, the lexical analyzer 161 a reads a quantum program from the area 151 of the temporary memory 150, analyzes the lexical analysis, and stores the lexical analysis result in the area 152. Next, the syntax analysis unit 161 b reads the lexical analysis result from the area 152 of the temporary memory 150, performs the syntax analysis, and stores the syntax analysis result in the area 153. Finally, the semantic analysis unit 161c reads the syntax analysis result from the area 153 of the temporary memory 150, performs the semantic analysis, and performs the semantic analysis result “class library designation information” “quantum processing description information” “classical processing description”. Information ”is stored in area 154. “Class library designation information”, “quantum processing description information”, and “classical processing description information” are the above-mentioned “class library designation information source code”, “quantum processing description information source code”, and “classical processing description information source code”. (See FIG. 6). The “quantum processing description information” extracted here corresponds to any of the quantum processing description information of the class libraries 200-1 to 200-n. Furthermore, for extracting quantum processing description information, for example, “RR Tucci, A Rudimentary Quantum Compiler (2nd edition), [online], [searched on May 20, 2005], Internet <http://arxiv.org / abs / quant-ph / 9902062> ”,“ RR Tucci, Qubiter Algorithm Modification, Expressing Unstructured Unitary Matrices with Fewer CNOTs), [online], [May 20, 2005 search], Internet <http: // arxiv .org / abs / quant-ph / 0411027> ”is used.

Next, the search unit 162 reads the class library designation information and the quantum processing description information extracted by the analysis unit 161 from the area 154 of the temporary memory 150, and stores the corresponding quantum gate information in the class library storage unit 140. Extracted from the stored class library (step S3).
In this example, the search unit 162 first extracts the class library associated with the class library identification information specified by the read class library specification information from the class library storage unit 140. For example, in the case of the quantum program 300 illustrated in FIG. 6, the search unit 162 stores the class library identification information “cstd1” 210-1 specified by the class library specifying information “cstd1lib” extracted from the class library specifying information source code 302. The associated class library 200-1 (FIG. 2B) is extracted from the class library storage unit 140. Next, the search unit 162 extracts quantum gate information associated with the read quantum processing description information in the extracted class library. In the case of the quantum program 300 illustrated in FIG. 6, the search unit 162 extracts quantum gate information associated with the read quantum processing description information in the extracted class library 200-1 (FIG. 2B). Thereafter, the search unit 162 stores the extracted quantum gate information in the area 155 of the temporary memory 150.

  Next, the quantum circuit generation unit 163 reads the quantum gate information extracted by the search unit 162 from the region 155 of the temporary memory 150, and if necessary, at least a part of the quantum description information from the region 154 (for example, the quantum gate is activated). Information relating to the qubit position to be generated), a quantum circuit is generated using them, and quantum circuit information indicating the quantum circuit is output (step S4). The generation of the quantum circuit here is performed by arranging each quantum gate information in time series, for example. In this example, the output quantum circuit information is stored in the area 156 of the temporary memory 150. FIG. 8 is an example of the quantum circuit 350 generated from the quantum processing description information source code 303 of the quantum program 300 illustrated in FIG. 6 by the processing as described above.

Next, the classic code generation unit 165 reads the classic process description information from the area 154 of the temporary memory 150, generates a classic object code (assembler, machine language, etc.) from these using a known method, and stores it in the area 157 ( Step S5).
Next, the linker unit 166 reads the quantum circuit information from the area 156 of the temporary memory 150 and the classic object code from the area 157, respectively. Then, the linker unit 166 forms a dynamic link between the quantum circuit information and the classical object code, and stores this link information in the area 158 (step S6).

Finally, the output unit 130 reads the quantum circuit information, the classical object code, and the link information from the areas 155, 157, and 158 of the temporary memory 150, and outputs them (step S7). The quantum circuit information, classic object code, and link information output in this way are input to a quantum computer (or a quantum simulator) and a classic computer, and each process is executed on them.
<Features of this embodiment>
In this mode, an optimal class library is set for each quantum system of the quantum computer, and conversion from the quantum program to the quantum circuit is performed using the optimal class library according to the quantum computer that implements the quantum program. I decided to do it. As a result, the programmer can write and execute the quantum program without being aware of the hardware differences of the quantum computer. For example, in the quantum program conversion apparatus 100 of this embodiment,
main {
qubit x [5], y [6];
y.qadd (x);
}
X + y is calculated from the inputs x and y, and the following quantum circuit corresponding to the difference in the quantum system can be automatically generated for the quantum program input to y. For example, the quantum program conversion apparatus 100 generates a quantum circuit by using a class library using a control rotation gate instead of the CNOT gate for a quantum system in which the control rotation gate is desired to be used rather than the CNOT gate. As a result, a quantum circuit having a universal gate composed of a qubit rotation gate and a control rotation gate as illustrated in FIG. 9A is generated. The quantum circuit of the QFT (quantum Fourier transform) part is as shown in FIG. On the other hand, the quantum program conversion apparatus 100 generates a quantum circuit using a class library using a CNOT gate for a quantum system in which it is desirable to use a CNOT gate. As a result, a quantum circuit having a universal gate composed of a 1-qubit rotation gate and a CNOT gate as illustrated in FIG. 9A is generated. However, in either case, the quantum program as seen from the programmer is the same.

In addition, even if the quantum system of the mounted quantum computer is changed, there is an advantage that the quantum program up to that point can be used continuously. Furthermore, a quantum simulator can be installed in the terminal device of the quantum computer, and debugging of the quantum program and execution of the quantum computer can be executed by the same terminal device. In a situation where it is difficult to maintain the computing environment of the quantum computer, this method will greatly benefit the development of the quantum program.
Further, as described in this embodiment, by using this technique, it is possible to describe a classical computer operation instruction and a quantum computer operation instruction in a quantum program. This makes it possible to program with the same feeling without distinguishing between a quantum computer and a classical computer from the viewpoint of a programmer.

<Second Embodiment>
This embodiment is a modification of the first embodiment, and differs from the first embodiment in that the quantum program is transformed into a quantum circuit capable of error correction. Below, it demonstrates centering around difference with 1st Embodiment, and abbreviate | omits description about the matter which is common in 1st Embodiment.
<Device configuration>
FIG. 11 is a block diagram illustrating a configuration of the quantum program conversion apparatus 400 according to the second embodiment. In this figure, the same reference numerals as those in FIG. 1 are assigned to portions common to the first embodiment.

  As illustrated in this figure, the quantum program conversion apparatus 400 of this embodiment includes a control unit 110, an input unit 120, an output unit 130, a class library storage unit 140, an error correction library storage unit 440, a temporary memory 150, and an analysis unit 161. , A search unit 162, 461, a quantum circuit generation unit 163, a classical code generation unit 165, and a linker unit 166, which convert the input quantum program into quantum circuit information and output it. The analysis unit 161 includes a lexical analysis unit 161a, a syntax analysis unit 161b, and a semantic analysis unit 161c, and the temporary memory 150 includes regions 151 to 158, 451, and 454. Further, description of the library used by the analysis unit 161 and the classical code generation unit 165 is omitted.

<Data structure>
The configuration of data stored in the class library storage unit 140 is the same as that in the first embodiment. Hereinafter, the configuration of data stored in the error correction library storage unit 440 will be described.
FIG. 12 is a conceptual diagram illustrating the state of the error correction libraries 500-1 to 500-m stored in the error correction library storage unit 440 illustrated in FIG.
As illustrated in FIG. 12, the error correction library storage unit 440 stores a plurality of error correction libraries 500-1 to 500-m. These error correction libraries 500-1 to 500-m are provided corresponding to the quantum systems of the quantum computers on which the quantum circuits generated from the quantum programs are mounted.

FIGS. 13A and 13B are conceptual diagrams illustrating data configurations of the error correction libraries 500-1 and 500-2 in FIG.
As illustrated in these figures, the error correction libraries 500-1 and 500-2 are error correction library identification information ("7qubitcode1" and "7qubitcode2") 510-1 and 2 corresponding to the quantum system of the quantum computer, respectively, and quantum gates. This is a table in which the information 520-1 and 520-2 and the error correction quantum gate information 530-1 and 530-2 converted from the quantum gate information 520-1 and 520-2 to a circuit configuration capable of error correction are associated with each other. Other error correction libraries have the same configuration. However, the error correction quantum gate information may differ depending on the difference in the quantum system of the computer, so that the data content itself of each error correction library is different for each error correction library. The quantum gate information in the error correction library may be the same as the quantum gate information in the class library, a quantum gate obtained by further decomposing the quantum gate indicated by the quantum gate information in the class library, or quantum gate information in the class library The information of the quantum gate which integrated the quantum gate shown by may be sufficient. An example of the error correction quantum gate is a 7 qubit error correction gate. The 7-qubit error correction and the conversion method therefor are described in detail in, for example, “Co-authored by Michael A. Nielsen and Isaac L. Chuang, translated by Tatsuya Kimura,“ Quantum Computer and Quantum Communication ”, Ohmsha.”

<Quantum program>
FIG. 14 is a diagram illustrating a quantum program 600 according to the second embodiment.
As illustrated in this figure, the quantum program 600 includes a classic processing description information source code 601 which is a source code describing processing contents in a classical computer, a class library designation information source for designating the class library identification information described above. A code 602, an error correction library identification information source code 603 for designating the above-described error correction library identification information, and a quantum processing description information source code 604 which is a source code describing processing contents in the quantum computer. . Note that the quantum processing description information source code 604 describes only the processing contents in the quantum computer, and does not describe specific information about the quantum circuit.

<Processing>
Next, the quantum program conversion process in the second embodiment will be described.
FIG. 15 is a flowchart for explaining the quantum program conversion process according to the second embodiment. Hereinafter, the quantum program conversion process of this embodiment will be described with reference to this figure.
First, a quantum program is input in the input unit 120, and the input quantum program is temporarily stored in the area 151 of the temporary memory 150 (step S11). Next, as in the first embodiment, the analysis unit 161 reads a quantum program from the area 151 of the temporary memory 150, and class library specification information and error for specifying class library identification information from the quantum program. Correction library designation information, quantum processing description information, and classical processing description information are extracted and stored in the area 454 of the temporary memory 150 (step S12). The “error correction library designation information” is extracted from the aforementioned “error correction library identification information source code” (see FIG. 14).

Next, as in the first embodiment, the (first) search unit 162 reads the class library designation information and the quantum processing description information extracted by the analysis unit 161 from the area 454 of the temporary memory 150. Is extracted from the class library stored in the class library storage unit 140 and stored in the region 155 (step S13).
Next, in the (second) search unit 461, the error correction library designation information (for example, “7qubitcode1lib”) extracted by the analysis unit 161 from the region 454 of the temporary memory 150 is read, and the quantum gate extracted by the search unit 162 from the region 155 Read information. Then, the search unit 461 corresponds the error correction quantum gate information corresponding to these to the error correction library (in the above example, the error correction library identification information (7 qubitcode1) 510-1) stored in the error correction library storage unit 440. The error correction library 500-1 is used.) (Step S14).

  Next, the quantum circuit generation unit 163 reads the error correction quantum gate information extracted by the search unit 461 from the region 155 of the temporary memory 150, and if necessary, at least part of the quantum description information (for example, the quantum gate) from the region 454. Information on the qubit position where the quat acts, etc.) is read and used to generate a quantum circuit, and quantum circuit information indicating the quantum circuit is output (step S15). Here, the generation of the quantum circuit is performed by arranging each error correction quantum gate information in time series, for example. In this example, the output quantum circuit information is stored in the area 156 of the temporary memory 150.

  FIG. 16 is an example of the quantum circuit 700 generated from the quantum processing description information source code 604 of the quantum program 600 illustrated in FIG. 14 by the processing as described above. 17A is a diagram illustrating the 7-qubit error correction H quantum gate circuit 710 (7-qubit error correction gate of Hadamard transform gate) in FIG. 16, and FIG. 17B is a 7-qubit error correction in FIG. It is the figure which illustrated control S quantum gate circuit 720 (7 qubit error correction gate of control S gate). FIG. 18 is a diagram illustrating the configuration of the 7-qubit syndrome detection / recovery quantum circuit in FIG.

Next, the classic code generation unit 165 reads the classic process description information from the area 454 of the temporary memory 150, generates a classic object code from these using a known method, and stores it in the area 157 (step S16).
Next, the linker unit 166 reads the quantum circuit information from the area 156 of the temporary memory 150 and the classic object code from the area 157, respectively. Then, the linker unit 166 forms a dynamic link between the quantum circuit information and the classic object code, and stores this link information in the area 158 (step S17).

Finally, in the output unit 130, the quantum circuit information, the classic object code, and the link information are read from the areas 155, 157, and 158 of the temporary memory 150, and these are output (step S18).
<Features of this embodiment>
In this embodiment, in addition to the first embodiment, an error correction library is provided for each quantum system of the quantum program, and conversion from the quantum gate information to the error correction quantum gate is performed while properly using the error correction library according to the quantum system. It was decided to construct a quantum circuit from these error correcting quantum gates. As a result, the programmer can describe the quantum program without being aware of the difference in hardware of the quantum computer, and can execute each processing by the quantum circuit capable of error correction.

  The present invention is not limited to the above-described embodiments. For example, the present invention may be applied to a quantum program that describes only the processing contents of a quantum computer, or may be applied to a quantum program that partially includes a description of a quantum circuit. Also good. In addition, the various processes described above are not only executed in time series according to the description, but may be executed in parallel or individually according to the processing capability of the apparatus that executes the processes or as necessary. Needless to say, other modifications are possible without departing from the spirit of the present invention.

Further, when the above-described configurations are realized by a computer, the processing contents of functions that each device should have are described by a program. The processing functions are realized on the computer by executing the program on the computer.
The program describing the processing contents can be recorded on a computer-readable recording medium. The computer-readable recording medium may be any medium such as a magnetic recording device, an optical disk, a magneto-optical recording medium, or a semiconductor memory. Specifically, for example, the magnetic recording device may be a hard disk device or a flexible Discs, magnetic tapes, etc. as optical disks, DVD (Digital Versatile Disc), DVD-RAM (Random Access Memory), CD-ROM (Compact Disc Read Only Memory), CD-R (Recordable) / RW (ReWritable), etc. As the magneto-optical recording medium, MO (Magneto-Optical disc) or the like can be used, and as the semiconductor memory, EEP-ROM (Electronically Erasable and Programmable-Read Only Memory) or the like can be used.

The program is distributed by selling, transferring, or lending a portable recording medium such as a DVD or CD-ROM in which the program is recorded. Furthermore, the program may be distributed by storing the program in a storage device of the server computer and transferring the program from the server computer to another computer via a network.
A computer that executes such a program first stores, for example, a program recorded on a portable recording medium or a program transferred from a server computer in its own storage device. When executing the process, the computer reads a program stored in its own recording medium and executes a process according to the read program. As another execution form of the program, the computer may directly read the program from the portable recording medium and execute processing according to the program, and the program is transferred from the server computer to the computer. Each time, the processing according to the received program may be executed sequentially. Also, the program is not transferred from the server computer to the computer, and the above-described processing is executed by a so-called ASP (Application Service Provider) type service that realizes the processing function only by the execution instruction and result acquisition. It is good. Note that the program in this embodiment includes information that is used for processing by an electronic computer and that conforms to the program (data that is not a direct command to the computer but has a property that defines the processing of the computer).

  In this embodiment, the present apparatus is configured by executing a predetermined program on a computer. However, at least a part of these processing contents may be realized by hardware.

  As an application field of the present invention, for example, a compiler or interpreter in a quantum computer or a quantum simulator can be exemplified.

FIG. 1 is a block diagram illustrating the configuration of the quantum program conversion apparatus according to the first embodiment. FIG. 2A is a conceptual diagram illustrating the state of the class library stored in the class library storage unit illustrated in FIG. FIG. 2B is a conceptual diagram illustrating the data configuration of the class library in FIG. FIG. 3 is a diagram illustrating a quantum gate indicated by the quantum processing description information. FIG. 4 is a diagram illustrating a quantum gate indicated by the quantum processing description information. FIG. 5A is a conceptual diagram illustrating the data configuration of the class library in FIG. FIG. 5B illustrates the contents of quantum gate information corresponding to the negative CNOT (y.CNOT (! X);) of the class library. FIG. 6 is a diagram illustrating a quantum program in the first embodiment. FIG. 7 is a flowchart for explaining the quantum program conversion processing according to the first embodiment. FIG. 8 is an example of a quantum circuit generated from the quantum processing description information source code of the quantum program illustrated in FIG. FIGS. 9A and 9B are diagrams illustrating a quantum circuit generated in this embodiment. FIG. 10 is a diagram illustrating a quantum circuit in a QFT (quantum Fourier transform) portion. FIG. 11 is a block diagram illustrating the configuration of the quantum program conversion device according to the second embodiment. FIG. 12 is a conceptual diagram illustrating the state of the error correction library stored in the error correction library storage unit illustrated in FIG. 13A and 13B are conceptual diagrams illustrating the data configuration of the error correction library in FIG. FIG. 14 is a diagram illustrating a quantum program according to the second embodiment. FIG. 15 is a flowchart for explaining the quantum program conversion process according to the second embodiment. FIG. 16 is an example of a quantum circuit generated from the quantum processing description information source code of the quantum program illustrated in FIG. 17A is a diagram illustrating the 7-qubit error correction H quantum gate circuit of FIG. 16, and FIG. 17B is a diagram illustrating the 7-qubit error correction control S quantum gate circuit of FIG. FIG. 18 is a diagram illustrating the configuration of the 7 qubit syndrome detection / recovery quantum circuit in FIG.

Explanation of symbols

100,400 Quantum program conversion device 140 Class library storage unit 440 Error correction library storage unit

Claims (8)

A quantum program conversion device for generating a quantum circuit from a quantum program having a source code in which processing contents by a quantum computer are described,
Class library identification information corresponding to the quantum system of the quantum computer, quantum processing description information describing processing contents by the quantum computer, and processing contents indicated by the quantum processing description information in the quantum computer corresponding to the class library identification information are realized. A class library storage unit that stores a class library associated with quantum gate information indicating a quantum gate suitable for
An analysis unit that receives a quantum program and extracts class library designation information and quantum processing description information for designating class library identification information from the quantum program;
A search unit for extracting the quantum gate information corresponding to the class library designation information and the quantum processing description information extracted by the analysis unit from the class library;
A quantum circuit generating unit that generates a quantum circuit using the quantum gate information extracted by the search unit, and outputs quantum circuit information indicating the quantum circuit;
A quantum program conversion device comprising: The quantum program conversion device according to claim 1,
The class library storage unit
A plurality of the class libraries respectively corresponding to a plurality of quantum systems;
A quantum program conversion device characterized by the above. A quantum program conversion device for generating a quantum circuit from a quantum program having a source code in which processing contents by a quantum computer are described,
Class library identification information corresponding to the quantum system of the quantum computer, quantum processing description information describing processing contents by the quantum computer, and processing contents indicated by the quantum processing description information in the quantum computer corresponding to the class library identification information are realized. A class library storage unit that stores a class library associated with quantum gate information indicating a quantum gate suitable for
Stores an error correction library that associates error correction library identification information corresponding to the quantum system of the quantum computer, quantum gate information, and error correction quantum gate information obtained by converting the quantum gate information into a circuit configuration capable of error correction. Error correction library storage unit,
When a quantum program is input, class library specification information for specifying class library identification information, error correction library specification information for specifying error correction library identification information, and quantum processing description information are extracted from the quantum program. An analysis unit to
A first search unit for extracting the quantum gate information corresponding to the class library designation information and the quantum processing description information extracted by the analysis unit from the class library;
A second search unit for extracting the error correction quantum gate information corresponding to the error correction library designation information extracted by the analysis unit and the quantum gate information extracted by the first search unit from the error correction library;
A quantum circuit generating unit that generates a quantum circuit using the error correction quantum gate information extracted by the second search unit, and outputs quantum circuit information indicating the quantum circuit;
A quantum program conversion device comprising: The quantum program conversion device according to claim 3,
The error correction library storage unit
A plurality of error correction libraries respectively corresponding to a plurality of quantum systems;
A quantum program conversion device characterized by the above. A quantum program conversion method for generating a quantum circuit from a quantum program having a source code in which processing contents by a quantum computer are described,
Class library identification information corresponding to the quantum system of the quantum computer, quantum processing description information describing processing contents by the quantum computer, and processing contents indicated by the quantum processing description information in the quantum computer corresponding to the class library identification information are realized. In a state in which the class library associated with the quantum gate information indicating the quantum gate suitable for performing is stored in the class library storage unit,
A step in which a quantum program is input to the analysis unit, and the analysis unit extracts class library designation information and quantum processing description information for designating class library identification information from the quantum program;
In the search unit, extracting the quantum gate information corresponding to the class library designation information and the quantum processing description information extracted by the analysis unit from the class library;
In the quantum circuit generation unit, a step of generating a quantum circuit using the quantum gate information extracted by the search unit and outputting quantum circuit information indicating the quantum circuit;
A quantum program conversion method comprising: A quantum program conversion method for generating a quantum circuit from a quantum program having a source code in which processing contents by a quantum computer are described,
Class library identification information corresponding to the quantum system of the quantum computer, quantum processing description information describing processing contents by the quantum computer, and processing contents indicated by the quantum processing description information in the quantum computer corresponding to the class library identification information are realized. A class library associated with quantum gate information indicating a quantum gate suitable for the storage is stored in the class library storage unit,
The error correction library associated with the error correction library identification information corresponding to the quantum system of the quantum computer, the quantum gate information, and the error correction quantum gate information obtained by converting the quantum gate information into a circuit configuration capable of error correction is an error. In the state stored in the correction library storage unit,
A quantum program is input to the analysis unit, and in the analysis unit, class library specification information for specifying class library identification information from the quantum program, and error correction library specification information for specifying error correction library identification information; Extracting quantum processing description information;
In the first search unit, extracting the quantum gate information corresponding to the class library designation information and the quantum processing description information extracted by the analysis unit from the class library;
In the second search unit, the error correction quantum gate information corresponding to the error correction library designation information extracted by the analysis unit and the quantum gate information extracted by the first search unit is extracted from the error correction library. Steps,
In the quantum circuit generation unit, generating a quantum circuit using the error correction quantum gate information extracted by the second search unit, and outputting quantum circuit information indicating the quantum circuit;
A quantum program conversion method comprising:   The program for functioning a computer as a quantum program conversion apparatus in any one of Claim 1 to 4.   A computer-readable recording medium storing the program according to claim 7.

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