论文标题
重量调整量子回路气体的参数化量子电路
Parametrized quantum circuit for weight-adjustable quantum loop gas
论文作者
论文摘要
由于最近通过实际量子设备上的量子电路实现了确切解决的复曲面代码模型的拓扑排序基态的成功激励[K. J. Satzinger {\ it等人}。，Science \ TextBf {374}，1237（2021）]，在这里，我们提出了一个具有相同真实效能的最佳结构的参数化量子电路（PQC），以代表具有调节加权型构型的量子循环气体。将这样的PQC与变分量子本素化器相结合，我们在具有任何磁场强度的外部磁场中获得了精确的量子电路表示，而系统无法解决。通过测量磁化和拓扑纠缠熵，在优化电路中进一步观察到该系统中的拓扑量子相变。
Motivated by the recent success of realizing the topologically ordered ground state of the exactly solvable toric code model by a quantum circuit on the real quantum device [K. J. Satzinger {\it et al}., Science \textbf{374}, 1237 (2021)], here we propose a parametrized quantum circuit (PQC) with the same real-device-performable optimal structure to represent quantum loop gas states with adjustably weighted loop configurations. Combining such a PQC with the variational quantum eigensolver, we obtain the accurate quantum circuit representation for the toric code model in an external magnetic field with any field strength, where the system is not exactly solvable. The topological quantum phase transition in this system is further observed in the optimized circuits by measuring the magnetization and topological entanglement entropy.
