论文标题
工程Floquet动力量子相变
Engineering Floquet Dynamical Quantum Phase Transition
论文作者
论文摘要
Floquet动力学量子相变(FDQPTS)通过及时可观察到的反复进行的非分析行为表示。在这项工作中,我们引入了一种无淬火和通用的方法,以针对纯净和混合浮子状态进行工程和控制FDQPT。通过将具有两个相应驾驶频率的时间周期性调制应用于一类自旋链模型,我们在每个驾驶期内都会发现多个FDQPT。返回概率的非分析尖缘形成了时域中的sublattice结构。值得注意的是,可以通过调整哈密顿参数和较高的驱动器频率来灵活控制这些牙尖的数量和时间分离。我们进一步采用了动态拓扑顺序参数(DTOP),该参数在DQPT发生时显示了量化的跳跃,以识别FDQPT的拓扑特征。我们的发现揭示了与多频驱动场进行工程非平衡相变的优势。
Floquet dynamical quantum phase transitions (FDQPTs) are signified by recurrent nonanalytic behaviors of observables in time. In this work, we introduce a quench-free and generic approach to engineer and control FDQPTs for both pure and mixed Floquet states. By applying time-periodic modulations with two commensurate driving frequencies to a general class of spin chain model, we find multiple FDQPTs within each driving period. The nonanalytic cusps of return probability form sublattice structures in time domain. Notably, the number and time-locations of these cusps can be flexibly controlled by tuning the Hamiltonian parameter and the higher frequency of the drive. We further employ the dynamical topological order parameter (DTOP), which shows a quantized jump whenever a DQPT happens, to identify the topological feature of FDQPTs. Our findings reveal the advantage of engineering nonequilibrium phase transitions with multi-frequency driving fields.