论文标题
淬灭后强相关的二维自旋晶格中的动力学量子相变
Dynamical quantum phase transitions in strongly correlated two-dimensional spin lattices following a quench
论文作者
论文摘要
动力学量子相变是目前在平衡中理解量子物质的目前努力的最前沿。除了一些确切可解决的模型外，对这些关键现象的预测通常取决于先进的数值方法。但是，这些方法主要限于一个维度，从而对二维系统进行了调查。在这里，我们提供了在二维中强相关的自旋晶格中动态量子相变的证据。为此，我们应用了最近开发的累积方法[Phys。 Rev. X 11，041018（2021）]在复杂的时间平面中确定Loschmidt振幅的零，并预测零的热力学线与实时轴的交叉点，其中发生动力学量子相变。我们发现具有铁磁或抗铁磁耦合的二维量子晶格的关键时期和XYZ模型。我们还展示了如何通过测量初始能量波动（例如在量子模拟器或其他工程量子系统中）来预测动态量子相变。
Dynamical quantum phase transitions are at the forefront of current efforts to understand quantum matter out of equilibrium. Except for a few exactly solvable models, predictions of these critical phenomena typically rely on advanced numerical methods. However, those approaches are mostly restricted to one dimension, making investigations of two-dimensional systems highly challenging. Here, we present evidence of dynamical quantum phase transitions in strongly correlated spin lattices in two dimensions. To this end, we apply our recently developed cumulant method [Phys. Rev. X 11, 041018 (2021)] to determine the zeros of the Loschmidt amplitude in the complex plane of time and predict the crossing points of the thermodynamic lines of zeros with the real-time axis, where dynamical quantum phase transitions occur. We find the critical times of a two-dimensional quantum Ising lattice and the XYZ model with ferromagnetic or antiferromagnetic couplings. We also show how dynamical quantum phase transitions can be predicted by measuring the initial energy fluctuations, for example, in quantum simulators or other engineered quantum systems.
