论文标题
通过非热系统中的动态检测出色点
Detecting Exceptional Point through Dynamics in Non-Hermitian Systems
论文作者
论文摘要
非热旋转时间逆转（RT） - 对称自旋模型具有两个不同的阶段，即整个频谱是真实的不间断阶段，并且含有复杂的特征性特征性的损坏相，从而指示过渡点，称为特殊点。我们报告说，Loschmidt Echo的动力学数量，即初始状态和最终状态之间的重叠以及相应的速率函数，可以忠实地预测平衡场景中已知的特殊点。特别是，当在不间断的阶段制备初始状态并且系统要么淬火到破碎或不间断的阶段时，我们在分析上证明，速率函数和平均loschmidt Echo可以区分爆炸中发生的淬火阶段或与均匀的磁场和交替磁场的离线阶段发生的淬火阶段，因此可以区分出均匀的磁场，并在此指示异常。此外，我们表明，即使在具有磁场的非热XYZ模型之类的模型中，这种数量也能够识别出特殊点，这只能在数值上求解。
Non-Hermitian rotation-time reversal (RT)-symmetric spin models possess two distinct phases, the unbroken phase in which the entire spectrum is real and the broken phase which contains complex eigenspectra, thereby indicating a transition point, referred to as an exceptional point. We report that the dynamical quantities, namely short and long time average of Loschmidt echo which is the overlap between the initial and the final states, and the corresponding rate function, can faithfully predict the exceptional point known in the equilibrium scenario. In particular, when the initial state is prepared in the unbroken phase and the system is either quenched to the broken or unbroken phase, we analytically demonstrate that the rate function and the average Loschmidt echo can distinguish between the quench occurred in the broken or the unbroken phase for the nearest-neighbor XY model with uniform and alternating magnetic fields, thereby indicating the exceptional point. Furthermore, we exhibit that such quantities are capable of identifying the exceptional point even in models like the non-Hermitian XYZ model with magnetic field which can only be solved numerically.
