论文标题
在具有脱合量子临界点的自旋链中的动力学量子相变
Dynamical quantum phase transitions in a spin chain with deconfined quantum critical points
论文作者
论文摘要
我们通过分析和数值研究了loschmidt回声和自旋链中的动力学阶参数，该参数具有二聚体状态和铁磁相之间的脱合相变。对于从二聚体状态到铁磁相的淬灭，我们发现该模型可以表现出以相关的二聚阶参数为特征的动力学量子相变。特别是，当将系统从majumdar-ghosh状态淬灭到铁磁ising状态时，我们发现通过分析通过分析计算Loschmidt ECHO和动态阶序参数来分析计算的经典ising阶段的经典伊辛链的精确映射。相比之下，对于从铁磁状态到二聚体状态的淬灭，该系统放松非常快，因此动态量子过渡可能只能在短时间内存在。我们揭示了在两个断裂的对称相的系统中可以发生动力学量子相变，并且淬灭动力学可能独立于平衡相变。
We analytically and numerically study the Loschmidt echo and the dynamical order parameters in a spin chain with a deconfined phase transition between a dimerized state and a ferromagnetic phase. For quenches from a dimerized state to a ferromagnetic phase, we find that the model can exhibit a dynamical quantum phase transition characterized by an associating dimerized order parameters. In particular, when quenching the system from the Majumdar-Ghosh state to the ferromagnetic Ising state, we find an exact mapping into the classical Ising chain for a quench from the paramagnetic phase to the classical Ising phase by analytically calculating the Loschmidt echo and the dynamical order parameters. By contrast, for quenches from a ferromagnetic state to a dimerized state, the system relaxes very fast so that the dynamical quantum transition may only exist in a short time scale. We reveal that the dynamical quantum phase transition can occur in systems with two broken symmetry phases and the quench dynamics may be independent on equilibrium phase transitions.
