Carollo Federico, Lesanovsky Igor
Institut für Theoretische Physik, Eberhard Karls Universität Tübingen, Auf der Morgenstelle 14, 72076 Tübingen, Germany.
School of Physics and Astronomy and Centre for the Mathematics and Theoretical Physics of Quantum Non-Equilibrium Systems, The University of Nottingham, Nottingham NG7 2RD, United Kingdom.
Phys Rev Lett. 2022 Jan 28;128(4):040603. doi: 10.1103/PhysRevLett.128.040603.
We introduce the concept of dark space phase transition, which may occur in open many-body quantum systems where irreversible decay, interactions, and quantum interference compete. Our study is based on a quantum many-body model that is inspired by classical nonequilibrium processes which feature phase transitions into an absorbing state, such as epidemic spreading. The possibility for different dynamical paths to interfere quantum mechanically results in collective dynamical behavior without classical counterpart. We identify two competing dark states, a trivial one corresponding to a classical absorbing state and an emergent one which is quantum coherent. We establish a nonequilibrium phase transition within this dark space that features a phenomenology which cannot be encountered in classical systems. Such emergent two-dimensional dark space may find technological applications, e.g., for the collective encoding of a quantum information.
我们引入了暗空间相变的概念，这种相变可能发生在开放的多体量子系统中，其中不可逆衰变、相互作用和量子干涉相互竞争。我们的研究基于一个量子多体模型，该模型受到经典非平衡过程的启发，这些过程具有向吸收态的相变特征，例如流行病传播。不同动力学路径进行量子力学干涉的可能性导致了没有经典对应物的集体动力学行为。我们识别出两种相互竞争的暗态，一种平凡的暗态对应于经典吸收态，另一种是量子相干的涌现暗态。我们在这个暗空间内建立了一种非平衡相变，其具有经典系统中不会出现的现象学特征。这种涌现的二维暗空间可能会有技术应用，例如用于量子信息的集体编码。
