Ergodicity-breaking and slow relaxation are intriguing aspects of nonequilibrium dynamics both in classical and in quantum settings. These phenomena are typically associated with phase transitions, e.g. the emergence of metastable regimes near a first-order transition or scaling dynamics in the vicinity of critical points. Despite being of fundamental interest the associated divergent time scales are a hindrance when trying to explore steady-state properties. Here we show that the relaxation dynamics of Markovian open quantum systems can be accelerated exponentially by devising an optimal unitary transformation that is applied to the quantum system immediately before the actual dynamics. This initial "rotation" is engineered in such a way that the state of the quantum system becomes orthogonal to the slowest decaying dynamical mode. We illustrate our idea -- which is inspired by the so-called Mpemba effect, i.e., water freezing faster when initially heated up -- by showing how to achieve an exponential speed-up in the convergence to stationarity in Dicke models, and how to avoid metastable regimes in an all-to-all interacting spin system.
Necessary conditions for the Markovian Mpemba effect
Technion-Israel Institute of Technology（以色列理工学院）；Schulich Faculty of Chemistry and Helen Diller Quantum Center, Technion-Israel Institute of Technology（舒利希化学学院与海伦·迪勒量子中心，以色列理工学院）
Operation Mpemba effect: Breakdown of resource-Markovianity of free dynamics
Institute of Physics, Chinese Academy of Sciences（中国科学院物理研究所）；School of Physical Sciences, University of Chinese Academy of Sciences（中国科学院大学物理科学学院）；School of Physics and Optoelectronics, South China University of Technology（华南理工大学物理与光电学院）；Beijing Academy of Quantum Information Sciences（北京量子信息科学研究院）；Hefei National Laboratory（合肥国家实验室）
Ergotropic Mpemba crossings in finite-dimensional quantum batteries
Harish-Chandra Research Institute（哈里什-昌德拉研究所）；Homi Bhabha National Institute（霍米·巴巴国立研究所）；Instytut Fizyki Teoretycznej, Wydział Fizyki, Astronomii i Informatyki Stosowanej, Uniwersytet Jagielloński（雅盖隆大学物理、天文学与应用信息学院理论物理研究所）
We consider open quantum systems whose dynamics is governed by a time-independent Markovian Lindblad Master equation. Such systems approach their stationary state on a timescale that is determined by the spectral gap of the generator of the Master equation dynamics. In the recent paper [Carollo et al., Phys. Rev. Lett. 127, 060401 (2021)] it was shown that under certain circumstances it is possible to exponentially accelerate the approach to stationarity by performing a unitary transformation of the initial state. This phenomenon can be regarded as the quantum version of the so-called Mpemba e…
Thermodynamic limits of the Mpemba effect: A unified resource theory analysis of correlation-enabled mechanisms
Kadir Has University（卡迪尔哈斯大学）；TÜBİTAK Informatics and Information Security Research Center (BİLGEM)（土耳其科学院信息与信息安全研究中心（BİLGEM））；University of Oxford（牛津大学）
Observation of quantum multi-Mpemba effect in a trapped-ion system
College of Science, National University of Defense Technology（国防科技大学理学院）；Hefei National Laboratory（合肥国家实验室）；School of Physics and Astronomy, and Centre for the Mathematics and Theoretical Physics of Quantum Non-equilibrium Systems, University of Nottingham（诺丁汉大学物理与天文学院及量子非平衡系统数学与理论物理中心）；Key Laboratory of Low-Dimensional Quantum Structures and Quantum Control of Ministry of Education, Department of Physics and Synergetic Innovation Center for Quantum Effects and Applications, Hunan Normal University（湖南师范大学物理科学与技术学院、低维量子结构与量子控制教育部重点实验室及量子效应与应用协同创新中心）
Witnessing non-stationary and non-Markovian environments with a quantum sensor
Weizmann Institute of Science（魏茨曼科学研究所）；Centro Atómico Bariloche, CONICET, CNEA（巴里洛切原子中心，阿根廷国家科学技术研究委员会，阿根廷核能委员会）；Instituto de Nanociencia y Nanotechnologia, CNEA, CONICET（纳米科学与技术研究所，阿根廷核能委员会，阿根廷国家科学技术研究委员会）；Instituto Balseiro, CNEA, Universidad Nacional de Cuyo（巴尔塞罗研究所，阿根廷核能委员会，门多萨国立大学）；Physikalisches Institut, Universität Stuttgart（斯图加特大学第三物理研究所）
In this work, we introduce an information-theoretic approach for considering changes in dynamics of finitely dimensional open quantum systems governed by master equations. This experimentally motivated approach arises from considering how the averages of system observables change with time and quantifies how non-stationary the system is during a given time regime. By drawing an analogy with the exponential decay, we are able to further investigate regimes when such changes are negligible according to the logarithmic scale of time, and thus the system is approximately stationary. While this is …
