Wang Yucheng, Zhang Long, Niu Sen, Yu Dapeng, Liu Xiong-Jun
Shenzhen Institute for Quantum Science and Engineering, and Department of Physics, Southern University of Science and Technology, Shenzhen 518055, China.
International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China.
Phys Rev Lett. 2020 Aug 14;125(7):073204. doi: 10.1103/PhysRevLett.125.073204.
The critical phases, being delocalized but nonergodic, are fundamental phases different from both the many-body localization and ergodic extended quantum phases, and have so far not been realized in experiment. Here we propose an incommensurate topological insulating model of AIII symmetry class to realize such critical phases through an optical Raman lattice scheme, which possesses a one-dimensional (1D) spin-orbit coupling and an incommensurate Zeeman potential. We show the existence of both noninteracting and many-body critical phases, which can coexist with the topological phase, and show that the critical-localization transition coincides with the topological phase boundary in noninteracting regime. The dynamical detection of the critical phases is proposed and studied in detail based on the available experimental techniques. Finally, we demonstrate how the proposed critical phases can be achieved within the current ultracold atom experiments. This work paves the way to observe the novel critical phases.
临界相是非定域但非遍历的，是不同于多体局域化和遍历扩展量子相的基本相，迄今为止尚未在实验中实现。在此，我们提出一种AIII对称类的非公度拓扑绝缘模型，通过光学拉曼晶格方案来实现这种临界相，该方案具有一维（1D）自旋轨道耦合和非公度塞曼势。我们展示了非相互作用和多体临界相的存在，它们可以与拓扑相共存，并表明在非相互作用区域，临界-局域化转变与拓扑相边界重合。基于现有的实验技术，我们详细提出并研究了临界相的动力学检测。最后，我们展示了如何在当前的超冷原子实验中实现所提出的临界相。这项工作为观察新型临界相铺平了道路。
