近日，大连理工大学的于长水及其研究团队取得一项新进展。经过不懈努力，他们提出基于相干性变化的量子速度极限。相关研究成果已于2024年10月22日在国际知名学术期刊《物理评论A》上发表。

该研究团队提出一种基于动力学过程中量子相干性变化的可达量子速度极限。这表明，对于一个二维量子态，总可以找到相应的动力学过程，驱动其沿着测地线演化到另一个具有特定相干性变化的状态。作为应用，他们研究了退相位和耗散动力学的相干性量子速度极限。

研究表明，退相干动力学可以达到相干性量子速度极限，并且具有相同布居数的态的退相干会比其他态更快。然而，耗散动力学则表现出相反的行为。此外，研究人员还通过对比说明了上述动力学中所提界限的更强紧密性。

据悉，相干性是量子信息处理中最基本的量子资源。物理系统获得相干性或发生退相干的速度是一个关键因素。

附：英文原文

Title: Quantum speed limit in terms of coherence variations

Author: Zi-yi Mai, Chang-shui Yu

Issue&Volume: 2024/10/22

Abstract: Coherence is the most fundamental quantum resource in quantum information processing. How fast a physical system gets coherence or decoherence is a critical ingredient. We present an attainable quantum speed limit based on the variation of quantum coherence subject to a dynamical process. It indicates that for a two-dimensional quantum state, one can always find corresponding dynamics driving it to evolve along the geodesic to another state with certain coherence variation. As applications, we study the coherence quantum speed limits of the dephasing and dissipative dynamics. It is shown that the dephasing dynamics can saturate our coherence quantum speed limit, and the decoherence of the state with identical populations will be faster than others. However, the dissipative dynamics have the opposite behavior. In addition, we illustrate a stronger tightness of our bound for the mentioned dynamics by comparison.

DOI: 10.1103/PhysRevA.110.042425

Source: https://journals.aps.org/pra/abstract/10.1103/PhysRevA.110.042425