Gillman Edward, Carollo Federico, Lesanovsky Igor
School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, United Kingdom.
Centre for the Mathematics and Theoretical Physics of Quantum Non-Equilibrium Systems, University of Nottingham, Nottingham NG7 2RD, United Kingdom.
Phys Rev Lett. 2021 Dec 3;127(23):230502. doi: 10.1103/PhysRevLett.127.230502.
We employ (1+1)-dimensional quantum cellular automata to study the evolution of entanglement and coherence near criticality in quantum systems that display nonequilibrium steady-state phase transitions. This construction permits direct access to the entire space-time structure of the underlying nonequilibrium dynamics, and allows for the analysis of unconventional correlations, such as entanglement in the time direction between the "present" and the "past." We show how the uniquely quantum part of these correlations-the coherence-can be isolated and that, close to criticality, its dynamics displays a universal power-law behavior on approach to stationarity. Focusing on quantum generalizations of classical nonequilibrium systems: the Domany-Kinzel cellular automaton and the Bagnoli-Boccara-Rechtman model, we estimate the universal critical exponents for both the entanglement and coherence. As these models belong to the one-dimensional directed percolation universality class, the latter provides a key new critical exponent, one that is unique to quantum systems.
我们采用（1 + 1）维量子元胞自动机来研究在显示非平衡稳态相变的量子系统中，临界附近纠缠与相干性的演化。这种构建方式允许直接获取基础非平衡动力学的整个时空结构，并能够分析非常规关联，比如“当前”与“过去”之间在时间方向上的纠缠。我们展示了这些关联中独特的量子部分——相干性——是如何被分离出来的，并且在接近临界时，其动力学在趋近平稳态时呈现出一种通用的幂律行为。聚焦于经典非平衡系统的量子推广：多马尼 - 金泽尔元胞自动机和巴尼奥利 - 博卡拉 - 雷希特曼模型，我们估算了纠缠和相干性的通用临界指数。由于这些模型属于一维有向渗流普适类，后者提供了一个关键的新临界指数，这是量子系统所特有的。
