论文标题
通用Landau-Zener制度在动态拓扑相变中
Universal Landau-Zener regimes in dynamical topological phase transitions
论文作者
论文摘要
在跨拓扑相变驱动的有限系统中，发现Chern数和Bott指数表现出不同的行为，具体取决于边界条件和晶格的可分性。对于周期性的边界条件，对于有限的相应晶格（或在热力学极限）中，Chern数不会改变。另一方面，对于具有周期性边界条件的不优量的晶格，Chern号可能会更改，并且对于具有开放边界条件的晶格可以更改BOTT索引。在这里，我们表明，这两个指数更改的田野的尺度表现出Landau-Zener和近乎绝热的机制，具体取决于驱动驱动力的强度上升和系统尺寸的速度。这些制度之前是拓扑指数不会改变的制度。后者是唯一在不变坡道速度下生存在热力学极限中的方案。然后，我们证明DC HALL响应可用于独立于拓扑指数的行为来检测拓扑相变。
In finite systems driven unitarily across topological phase transitions, the Chern number and the Bott index have been found to exhibit different behaviors depending on the boundary conditions and on the commensurability of the lattice. For periodic boundary conditions, the Chern number does not change for finite commensurate lattices (or in the thermodynamic limit). On the other hand, the Chern number can change for incommensurate lattices with periodic boundary conditions and the Bott index can change for lattices with open boundary conditions. Here we show that the scalings of the fields at which those two indices change exhibit Landau-Zener and near-adiabatic regimes depending on the speed at which the strength of the drive is ramped up and on the system size. Those regimes are preceded by a regime in which the topological indices do not change. The latter is the only regime that, for nonvanishing ramp speeds, survives in the thermodynamic limit. We then show that the dc Hall response can be used to detect topological phase transitions independently of the behavior of the topological indices.
