Quantum-Inspired Reconfigurable Processor

由于量子计算机可以同时验证所有候选解，因此有望以高速解决NP问题，例如因式分解。然而，量子计算机的最终系统仍不清楚。指出要实现实际运行，不仅需要硬件，还需要软件，包括算法和基准测试。因此，需要一个量子计算模拟器来检验该算法。然而，大规模量子算法的仿真是困难的，因为量子计算机中使用了量子叠加，并且需要2^N的存储器来模拟N个量子位。本文提出了一种新的量子计算仿真器，将一些量子比特替换为经典的量子比特，并利用量子宏运算。在该仿真器中，我们只关注核心计算部分，对某些计算过程分配经典位，对频繁的量子运算使用一元宏运算。因此，我们成功地减少了内存使用。在实现上，我们在FPGA上制作了一个具有192个并行PE的双指令多数据处理器，时钟为40MHz，操作转换器为c语言软件，控制处理和一元宏操作。在这个量子计算仿真器中，我们利用量子计算机中著名的Shor算法对一个64位整数进行了因数分解实验。虽然这个计算相当于在量子计算机上使用320量子位的计算复杂度，但实验结果表明，这个模拟只需要1300秒的计算时间，并且只需要40k位的内存

A quantum computer is expected to solve the NP problem, such as factorization, at high speed, since it can verify all the solution candidates simultaneously. However, the final system of the quantum computer is still unclear. It is noted that not only hardware but also software with algorithm and benchmark tests is indispensable to realize practical operation. Hence, a quantum-computing emulator is necessary to inspect the algorithm. However, emulation of large-scale quantum algorithm is difficult, since quantum superposition is utilized in the quantum computer and 2^N memories are necessary to emulate N qubits. By replacing some qubits with classic bits and using quantum-macro operations, we have proposed a new quantum-computing emulator. In this emulator, by focusing on only a core calculation part, we have assigned classical bits for some calculation process and using unitary-macro operations for frequent quantum operations. As a result, we have succeeded to reduce memory usage. In implementation, we have fabricated a DIMD (dual-instruction multiple-data) processor with 192 parallel PE on FPGA with 40MHz clock and an operation converter which is a C-language software controlling processing and the unitary-macro operations. In this quantum-computing emulator, we have made an experiment on the factorization with a 64 bits integer by using Shor's algorithm, which is well-known algorithm for the quantum computer. Although this calculation is equivalent to computational complexity to use 320 qubit for on the quantum computer, as a result of experiment, 1,300 seconds are used for computation and only 40k-bit memory is required for this emulation