论文标题
介质浮雕系统热化的通用类别
Universality classes of thermalization for mesoscopic Floquet systems
论文作者
论文摘要
我们确定了热化的几个阶段，这些阶段描述了孤立的，定期驱动的（Floquet），中镜量子混沌系统的行为方式。我们还确定了一个新的Floquet热线集合 - 梯子合奏 - 在质量上与无特征的无限温度状态不同，该状态通常被认为描述了驱动系统的平衡。该阶段可以通过（i）不可逆地将订单$ω$的能量与驱动器（即floquet Thermalize thermalize of Thermalize of Thermalize of Drief）进行粗略分类。 These phases represent regimes of behavior in mesoscopic systems, but they are sharply defined in a large-system limit where the drive frequency $ω$ scales up with system size $N$ as the $N\to\infty$ limit is taken: we examine frequency scalings ranging from a weak $ω\sim \log N$, to stronger scalings ranging from $ω\sim \sqrt{N}$ to $ω\ sim n $。我们表明，Floquet热化分解的过渡发生在$ω\ sim n $以外，除此之外，根据浮雕区的存在或不存在罕见的共振，可以区分不浮动热化的系统。我们产生的热相图与小尺度量子模拟器的浮雕系统的数值研究和实验研究相关，这两者都缺乏尺度之间的分离。对我们作品的一个惊人的预测是，在完美的隔离下，简单纯初始状态的某些逼真的淬火协议可以显示出浮雕的热化，以使新型的schrodinger-cat状态在不同的温度下是状态的全球叠加。我们的工作扩展并组织了浮部分热，加热和平衡的理论，以介绍介质量子系统的设置。
We identify several phases of thermalization that describe regimes of behavior in isolated, periodically driven (Floquet), mesoscopic quantum chaotic systems. We also identify a new Floquet thermal ensemble -- the ladder ensemble -- that is qualitatively distinct from the featureless infinite-temperature state that is often assumed to describe the equilibrium of driven systems. The phases can be coarsely classified by (i) whether or not the system irreversibly exchanges energy of order $ω$ with the drive, i.e., Floquet thermalizes, and (ii) the ensemble describing the final equilibrium in systems that do Floquet thermalize. These phases represent regimes of behavior in mesoscopic systems, but they are sharply defined in a large-system limit where the drive frequency $ω$ scales up with system size $N$ as the $N\to\infty$ limit is taken: we examine frequency scalings ranging from a weak $ω\sim \log N$, to stronger scalings ranging from $ω\sim \sqrt{N}$ to $ω\sim N$. We show that the transition where Floquet thermalization breaks down occurs at $ω\sim N$ and, beyond that, systems that do not Floquet thermalize are distinguished based on the presence or absence of rare resonances across Floquet zones. We produce a thermalization phase diagram that is relevant for numerical studies of Floquet systems and experimental studies on small-scale quantum simulators, both of which lack a separation of scales between $N$ and $ω$. A striking prediction of our work is that, under perfect isolation, certain realistic quench protocols from simple pure initial states can show Floquet thermalization to a novel type of Schrodinger-cat state that is a global superposition of states at distinct temperatures. Our work extends and organizes the theory of Floquet thermalization, heating, and equilibrium into the setting of mesoscopic quantum systems.
