一种提高量子线路保真度的映射方法

A mapping method to improve fidelity of quantum circuits

摘要:

由噪声导致的双量子比特门操作错误是可逆的量子线路执行结果保真度下降的重要原因。提出一种将量子线路映射至含噪声量子计算设备的策略，提高量子线路在量子计算设备上的执行成功率。该策略给出一种寻找近邻路径方法，用于在量子比特不是全连通的量子计算设备上找出2个量子比特的近邻路径；由于在近邻路径上任意2个近邻量子比特的噪声一般不同，基于近邻路径上的双量子比特门执行成功率构建启发式函数，估算前瞻窗口内的线路保真度，并根据该代价函数选择保真度最高的近邻方式。通过测试多个Benchmarks，实验结果表明，与Qiskit工具包中SabreSwap和BasicSwap算法相比，本文所提策略的量子线路保真度平均提高65.67%和71.60%。该方法可以提高量子线路保真度。

Abstract:

The error of the double-qubit gate operation caused by the noise is an important reason for the reduction of the fidelity of the execution result in the reversible quantum circuit. A strategy for mapping quantum circuits to noisy quantum computing devices is proposed, so as to improve the success rate of quantum circuits on quantum computing devices. This strategy first provides a method for finding the neighbor path of two qubits on a quantum computing device in which the qubits are not fully connected; since the noise of any two neighbor qubits on the neighbor path is generally different, a heuristic function is constructed based on the execution success rate of the double-qubit gate on the nearest neighbor path to estimate the fidelity of the line in the look-ahead window, and the nearest neighbor method with the highest fidelity is selected according to the cost function. After testing multiple Benchmarks, the experimental results show that the proposed strategy improves the fidelity of the quantum circuit by an average of 65.67% and 71.60% respectively compared with the SabreSwap and BasicSwap methods in Qiskit. The proposed method can improve the fidelity of quantum circuits