Signatures of Quantum Phase Transitions after Quenches in Quantum Chaotic One-Dimensional Systems
Signatures of Quantum Phase Transitions after Quenches in Quantum Chaotic One-Dimensional Systems
复制标题
一维量子混沌系统猝灭后的量子相变特征
DOI：
10.1103/physrevx.11.031062
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发表时间：
2020-04
影响因子：
12.5
通讯作者：
A. Haldar;Krishnanand Mallayya;M. Heyl;F. Pollmann;M. Rigol;Arnab Das
中科院分区：
文献类型：
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作者：
A. Haldar;Krishnanand Mallayya;M. Heyl;F. Pollmann;M. Rigol;Arnab Das
量子相变是理解量子物质平衡低温特性的核心。无论是通过理论技术还是实验，定位它们都是具有挑战性的。在这里，我们证明了迫使系统强烈脱离平衡的反策略可以提供一种识别量子相变特征的途径。通过猝灭量子混沌（不可积分）自旋链，我们发现当猝灭参数接近临界值时，基态发生量子相变，局部可观测值在其中间时间动力学中表现出明显的特征。我们发现平衡后预期类热态的有效温度在猝灭参数的量子临界值附近有最小值，这与观测物的实时动力学特征有关。我们还探讨了具有拓扑跃迁的模型中量子临界点的动态非平衡特征，并讨论了如何在里德伯原子系统中获得我们的实验结果。
Quantum phase transitions are central for the understanding of the equilibrium low-temperature properties of quantum matter. Locating them can be challenging both by means of theoretical techniques as well as for experiments. Here, we show that the antithetic strategy of forcing a system strongly out of equilibrium can provide a route to identify signatures of quantum phase transitions. By quenching a quantum chaotic (nonintegrable) spin chain, we find that local observables can exhibit distinct features in their intermediate-time dynamics, when the quench parameter is close to its critical value, where the ground state undergoes a quantum phase transition. We find that the effective temperature in the expected thermal-like states after equilibration exhibits a minimum in the vicinity of the quantum critical value of the quench parameter, correlating with the features in the real-time dynamics of observables. We also explore dynamical nonequilibrium signatures of a quantum critical point in a model with a topological transition, and discuss how to access our results experimentally in systems of Rydberg atoms.