Title: Hybrid quantum-classical simulation of quantum speed limits in open quantum systems Show Chinese title

Title: 开放量子系统中量子速度极限的混合量子经典模拟

Abstract: The quantum speed limit (QSL) provides a fundamental upper bound on the speed of quantum evolution, but its evaluation in generic open quantum systems still presents a formidable computational challenge. Herein, we introduce a hybrid quantum-classical method for computing QSL times in multi-level open quantum systems. The method is based on a mixed Wigner-Heisenberg representation of the composite quantum dynamics, in which the open subsystem of interest is treated quantum mechanically and the bath is treated in a classical-like fashion. By solving a set of coupled first-order deterministic differential equations for the quantum and classical degrees of freedom, one can compute the QSL time. To demonstrate the utility of the method, we study the unbiased spin-boson model and provide a detailed analysis of the effect of the subsystem-bath coupling strength and bath temperature on the QSL time. In particular, we find a turnover of the QSL time in the strong coupling regime, which is indicative of a speed-up in the quantum evolution. We also apply the method to the Fenna- Matthews-Olson complex model and identify a potential connection between the QSL time and the efficiency of the excitation energy transfer at different temperatures. Show Chinese abstract

Abstract: 量子速度极限（QSL）为量子演化的速度提供了基本的上限，但在通用开放量子系统中的评估仍然存在巨大的计算挑战。 在此，我们引入一种混合量子-经典方法，用于计算多级开放量子系统的QSL时间。 该方法基于复合量子动力学的混合Wigner-Heisenberg表示，在该表示中，感兴趣的开放子系统被量子力学地处理，而环境则以类经典的方式处理。 通过求解量子和经典自由度的一组耦合一阶确定性微分方程，可以计算QSL时间。 为了展示该方法的实用性，我们研究了无偏自旋-玻色子模型，并详细分析了子系统-环境耦合强度和环境温度对QSL时间的影响。 特别是，我们在强耦合区域发现了QSL时间的转变，这表明量子演化速度有所加快。 我们还将该方法应用于Fenna-Matthews-Olson复合体模型，并在不同温度下识别出QSL时间与激发能传输效率之间的潜在联系。