论文标题
通过避免的跨度光谱法估算定期驱动的量子多体系统的加热时间
Estimating heating times in periodically driven quantum many-body systems via avoided crossing spectroscopy
论文作者
论文摘要
量子（或经典）多体系统的周期性驾驶可以显着改变系统性能，因此已成为一种有前途的外来量子阶段的有前途的方法，例如拓扑绝缘子和离散的时间晶体。这种设置的主要限制是，通常相互作用的，驱动的系统会随着时间的推移而加热并失去所需的属性。因此，了解相关的时间尺度是该领域的一个重要主题，到目前为止，只有很少的方法可以定量和计算上有效的方式来确定混凝土系统的加热时间。在本文中，我们提出了一种新方法，基于从微观过程中构建加热速率，并在避免了浮标传播器的水平穿越中编码。我们开发了一种能够解决各个交叉口并显示如何基于这些交叉构建加热率的方法。该方法与弱驱动器的费米黄金法则方法密切相关，但可以超越该方法，因为它通过构造捕获了非扰动效应。这使我们的方法适用于诸如离散时间晶体的加热时间或频率依赖耦合的情况，这些耦合与Floquet Engineering非常相关，在此之前，以前没有可用的有效方法来估算加热时间。
Periodic driving of a quantum (or classical) many-body system can alter the systems properties significantly and therefore has emerged as a promising way to engineer exotic quantum phases, such as topological insulators and discrete time crystals. A major limitation in such setups, is that generally interacting, driven systems will heat up over time and lose the desired properties. Understanding the relevant time scales is thus an important topic in the field and so far, there have only been few approaches to determine heating times for a concrete system quantitatively, and in a computationally efficient way. In this article we propose a new approach, based on building the heating rate from microscopic processes, encoded in avoided level crossings of the Floquet propagator. We develop a method able to resolve individual crossings and show how to construct the heating rate based on these. The method is closely related to the Fermi Golden Rule approach for weak drives, but can go beyond it, since it captures non-perturbative effects by construction. This enables our method to be applicable in scenarios such as the heating time of discrete time crystals or frequency dependent couplings, which are very relevant for Floquet engineering, where previously no efficient methods for estimating heating times were available.
