arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2303.05089quant-phcs.NAmath.DSmath.NA
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复合开放量子系统的绝热消去:约化模型构建与数值模拟

Adiabatic elimination for composite open quantum systems: reduced model formulation and numerical simulations

François-Marie Le Régent, Pierre Rouchon

AI总结:

针对复合开放量子系统模拟难题,提出基于Lindblad主方程与绝热消去的约化数值方法,仅需局域计算即可实现二阶展开,适用于自主量子纠错,在多猫量子比特门模拟中大幅降低计算成本且精度达标。

摘要:

本文提出了一种用于模拟复合开放量子系统的数值方法,该方法基于Lindblad主方程与绝热消去技术。研究假设每个子系统会指数收敛至一个定常子空间,仅受部分退相干通道的微弱影响,且与其他子系统间为弱耦合关系。该数值方法以带渐近展开的微扰分析为基础,利用降维形式描述慢动力学,依赖于每个子系统对应的局域标称耗散动力学的不变算符,仅通过局域数值计算即可完成二阶展开,避免了在全系统对应的张量积希尔伯特空间上开展计算,尤其适用于自主量子纠错方案。针对作用于1个和2个猫量子比特的典型门(Z、ZZ与CNOT门),当每个猫量子比特的平均光子数小于8时,约化模型的模拟结果与完整全模型模拟结果一致。对于平均光子数更大的情况以及3个猫量子比特的门(ZZZ与CCNOT门),全模型模拟几乎无法实现,而约化模型模拟仍可开展,且能同时捕捉到主导的相位翻转错误率,以及随平均光子数呈指数抑制的极小比特翻转错误率。

英文摘要:

A numerical method is proposed for simulation of composite open quantum systems. It is based on Lindblad master equations and adiabatic elimination. Each subsystem is assumed to converge exponentially towards a stationary subspace, slightly impacted by some decoherence channels and weakly coupled to the other subsystems. This numerical method is based on a perturbation analysis with an asymptotic expansion. It exploits the formulation of the slow dynamics with reduced dimension. It relies on the invariant operators of the local and nominal dissipative dynamics attached to each subsystem. Second-order expansion can be computed only with local numerical calculations. It avoids computations on the tensor-product Hilbert space attached to the full system. This numerical method is particularly well suited for autonomous quantum error correction schemes. Simulations of such reduced models agree with complete full model simulations for typical gates acting on one and two cat-qubits (Z, ZZ and CNOT) when the mean photon number of each cat-qubit is less than 8. For larger mean photon numbers and gates with three cat-qubits (ZZZ and CCNOT), full model simulations are almost impossible whereas reduced model simulations remain accessible. In particular, they capture both the dominant phase-flip error-rate and the very small bit-flip error-rate with its exponential suppression versus the mean photon number.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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