论文标题
各向异性拓扑结构安德森在手性对称类别中的过渡
Anisotropic Topological Anderson Transitions in Chiral Symmetry Classes
论文作者
论文摘要
我们研究手性类别（AIII和BDI）中三维无序系统的量子相变，有和没有较弱的拓扑指数。我们表明，具有非平凡弱拓扑指数的系统普遍表现出一个新兴的热力学相，其中波函数沿一个空间方向定位，但在其他两个空间方向上呈指数式定位，我们称之为quasi-localized阶段。我们的广泛数值研究澄清说，金属和准定位相之间的安德森过渡的关键指数，以及准定位和局部阶段之间的临界指数与没有弱拓扑指数不同，这表明了拓扑引起的新普遍性类别。准定位的相位和伴随拓扑的安德森过渡在无序的弱拓扑绝缘子和淋巴结线半法的各向异性转运现象中表现出来，这些现象在一个方向上表现出金属行为，但在其他方向上表现出绝缘行为。
We study quantum phase transitions of three-dimensional disordered systems in the chiral classes (AIII and BDI) with and without weak topological indices. We show that the systems with a nontrivial weak topological index universally exhibit an emergent thermodynamic phase where wave functions are delocalized along one spatial direction but exponentially localized in the other two spatial directions, which we call the quasi-localized phase. Our extensive numerical study clarifies that the critical exponent of the Anderson transition between the metallic and quasi-localized phases, as well as that between the quasi-localized and localized phases, are different from that with no weak topological index, signaling the new universality classes induced by topology. The quasi-localized phase and concomitant topological Anderson transition manifest themselves in the anisotropic transport phenomena of disordered weak topological insulators and nodal-line semimetals, which exhibit the metallic behavior in one direction but the insulating behavior in the other directions.
