论文标题
非热浮标阶段的双重拓扑表征
Dual topological characterization of non-Hermitian Floquet phases
论文作者
论文摘要
预计非热性将为物质的浮雕拓扑阶段增加更多的物理特征。然而，仍然缺乏一种系统的表征非福尔奎特拓扑问题的系统方法。在这项工作中，我们介绍了一种双重方案，以使用分段淬灭的非重点su-schrieffer-heeger模型来表征动量空间和真实空间中非富尔浮标系统的拓扑。在周期性的边界条件下，拓扑阶段的特征是一对实验可访问的绕组数字，使整数和半智商之间跳跃。在开放的边界条件下，发现所谓的开放边界绕组数的Floquet版本是整数，并且可以预测零的对数和$π$ floquet Edge模式与非铁皮皮肤效应共存。我们的结果表明，对于非热浮标拓扑问题的双重表征是必要的，而且也是可行的，因为可以避免为具有多个跳高长度尺度的非热浮标系统构建著名的广义Brillouin区域的艰巨任务。因此，这项工作为在非平衡系统中进一步研究非炎性物理学的方法铺平了一种方法。
Non-Hermiticity is expected to add far more physical features to the already rich Floquet topological phases of matter. Nevertheless, a systematic approach to characterize non-Hermitian Floquet topological matter is still lacking. In this work we introduce a dual scheme to characterize the topology of non-Hermitian Floquet systems in momentum space and in real space, using a piecewise quenched nonreciprocal Su-Schrieffer-Heeger model for our case studies. Under the periodic boundary condition, topological phases are characterized by a pair of experimentally accessible winding numbers that make jumps between integers and half-integers. Under the open boundary condition, a Floquet version of the so-called open boundary winding number is found to be integers and can predict the number of pairs of zero and $π$ Floquet edge modes coexisting with the non-Hermitian skin effect. Our results indicate that a dual characterization of non-Hermitian Floquet topological matter is necessary and also feasible because the formidable task of constructing the celebrated generalized Brillouin zone for non-Hermitian Floquet systems with multiple hopping length scales can be avoided. This work hence paves a way for further studies of non-Hermitian physics in non-equilibrium systems.
