论文标题
与远距离耦合相互作用的费米子的准体定位
Quasi-Many-Body Localization of Interacting Fermions with Long-Range Couplings
论文作者
论文摘要
从偶极系统到捕获的离子，许多用于量子量子物质的量子模拟的实验平台涉及的自由度，这些自由度与幂律衰减的跳跃或相互作用相结合，但这些系统中的混乱和相互作用的相互作用与短期相对组相比，这些系统的相互作用和相互作用的相互作用远不足。在这里，我们考虑了一种与无序的长期跳跃和相互作用相互作用的Fermions的原型模型，并使用流程方程方法将其动力学相图映射为跳和交互指数的函数。我们证明，由于其能够准确模拟非常大的系统尺寸的能力，因此理想情况下，流动方程技术非常适合涉及远程耦合的问题。我们表明，在大型现场障碍和短距离相互作用下，随着跳跃范围的降低，存在从离域阶段到准多体局部（MBL）相的过渡。该准MBL相具有有趣的特性，例如一组紧急的保守量，它们会随着距离而衰减代数。令人惊讶的是，我们发现即使存在远距离相互作用，离域和准MBL相之间的跨界也可以生存。
A number of experimental platforms for quantum simulations of disordered quantum matter, from dipolar systems to trapped ions, involve degrees of freedom which are coupled by power-law decaying hoppings or interactions, yet the interplay of disorder and interactions in these systems is far less understood than in their short-ranged counterpart. Here we consider a prototype model of interacting fermions with disordered long-ranged hoppings and interactions, and use the flow equation approach to map out its dynamical phase diagram as a function of hopping and interaction exponents. We demonstrate that the flow equation technique is ideally suited to problems involving long-range couplings due to its ability to accurately simulate very large system sizes. We show that, at large on-site disorder and for short-range interactions, a transition from a delocalized phase to a quasi many-body localized (MBL) phase exists as the hopping range is decreased. This quasi-MBL phase is characterized by intriguing properties such as a set of emergent conserved quantities which decay algebraically with distance. Surprisingly we find that a crossover between delocalized and quasi-MBL phases survives even in the presence of long-range interactions.
