论文标题
无序诱导的非铁阶段的介镜运输特征
Mesoscopic transport signatures of disorder-induced non-Hermitian phases
论文作者
论文摘要
我们研究了对无序的特殊点（EP）的基本量子传输特性的影响，该特性在毫无疾病平均的绿色功能描述中出现，对具有自旋或轨道依赖性潜在散射的二维（2D）DIRAC半法。值得注意的是，我们发现EPS可能会促进DIRAC点有限样本的几乎消失的电导率，从而随着无序强度而增加。这种引人注目的行为表现出强烈的方向各向异性，该方向与连接EPS的费米弧密切相关。我们通过数值精确的仿真来证实我们的结果，从而揭示了特征性非热光谱特征的指纹在考虑系统的定位属性上。最后，讨论了几个用于实验验证我们理论分析的候选者，包括电子方形材料无序的材料和冷依赖性光学晶格中的冷原子。
We investigate the impact on basic quantum transport properties of disorder-induced exceptional points (EPs) that emerge in a disorder-averaged Green's function description of two-dimensional (2D) Dirac semimetals with spin- or orbital-dependent potential scattering. Remarkably, we find that EPs may promote the nearly vanishing conductance of a finite sample at the Dirac point to a sizable value that increases with disorder strength. This striking behavior exhibits a strong directional anisotropy that is closely related to the Fermi arcs connecting the EPs. We corroborate our results by numerically exact simulations, thus revealing the fingerprints of characteristic non-Hermitian spectral features also on the localization properties of the considered systems. Finally, several candidates for the experimental verification of our theoretical analysis are discussed, including disordered electronic square-net materials and cold atoms in spin-dependent optical lattices.
