论文标题
可集成的非热模型的Floquet动力学中的新兴保护
Emergent conservation in Floquet dynamics of integrable non-Hermitian models
论文作者
论文摘要
我们使用以振幅$ g_1 $和频率$ω_d$为特征的连续驱动协议定期驱动的一类可集成的非热自由化模型的动力学。我们得出了一种分析性的，尽管是扰动性的Floquet Hamiltonian，用于使用Floquet扰动理论描述此类系统，其中$ G_1^{ - 1} $是扰动参数。我们的分析表明，出现大约保守数量的特殊驱动频率存在。这种几乎保守的数量的存在反映在忠诚度，相关函数和驱动系统的半链纠缠熵的动力学中。此外，它还控制系统稳态的性质。我们表明，具有横向场的假想成分的一维（1D）横向场Ising模型是该现象的实验相关示例。在这种情况下，横向磁化值大约是保守的。这种保护导致在特殊驱动频率下的保真度，磁化和纠缠的瞬时动力学中完全抑制了振荡特征。我们通过展示其在离散驱动方案方面的存在，并建议可以测试我们的理论，从而讨论了附近和远离这些特殊频率附近和远离这些特殊频率的稳态的性质，证明了这种现象的协议独立性。
We study the dynamics of a class of integrable non-Hermitian free-fermionic models driven periodically using a continuous drive protocol characterized by an amplitude $g_1$ and frequency $ω_D$. We derive an analytic, albeit perturbative, Floquet Hamiltonian for describing such systems using Floquet perturbation theory with $g_1^{-1}$ being the perturbation parameter. Our analysis indicates the existence of special drive frequencies at which an approximately conserved quantity emerges. The presence of such an almost conserved quantity is reflected in the dynamics of the fidelity, the correlation functions and the half-chain entanglement entropy of the driven system. In addition, it also controls the nature of the steady state of the system. We show that one-dimensional (1D) transverse field Ising model, with an imaginary component of the transverse field, serves as an experimentally relevant example of this phenomenon. In this case, the transverse magnetization is approximately conserved; this conservation leads to complete suppression of oscillatory features in the transient dynamics of fidelity, magnetization, and entanglement of the driven chain at special drive frequencies. We discuss the nature of the steady state of the Ising chain near and away from these special frequencies, demonstrate the protocol independence of this phenomenon by showing its existence for discrete drive protocols, and suggest experiments which can test our theory.
