论文标题
从临界量子淬灭的动力量子相变
Dynamical quantum phase transition from a critical quantum quench
论文作者
论文摘要
我们研究了临界量子淬灭的动力学量子相变，其中预灭的哈密顿量或衡量后的哈密顿量或两者都将成为平衡量子相变的关键点，我们发现半定量或单位量化的动态拓扑阶数参数和动态的Chern数量；这些结果以及动态量子相变的存在与在闭合闭合动量下的Bogoliubov角度的奇异性密切相关。如果预先衡量和衡量的哈密顿人都至关重要，那么奇异性的效果也可能会被取消，然后动态拓扑顺序参数和动力学Chern数恢复到整数。我们的发现表明，在拓扑的角度来看，动态拓扑顺序参数和动力学的Chern编号的广泛接受定义对于关键淬火是有问题的，这些拓扑的角度要求其新的定义。
We study the dynamical quantum phase transition of the critical quantum quench, in which the prequenched Hamiltonian, or the postquenched Hamiltonian, or both of them are set to be the critical points of equilibrium quantum phase transitions, we find half-quantized or unquantized dynamical topological order parameter and dynamical Chern number; these results and also the existence of dynamical quantum phase transition are all closely related to the singularity of the Bogoliubov angle at the gap-closing momentum. The effects of the singularity may also be canceled out if both the prequenched and postquenched Hamiltonians are critical, then the dynamical topological order parameter and dynamical Chern number restore to integer ones. Our findings show that the widely accepted definitions of dynamical topological order parameter and dynamical Chern number are problematic for the critical quenches in the perspective of topology, which call for new definitions of them.
