Mesoscopic transport signatures of disorder-induced non-Hermitian phases

Abstract

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.

References in corpus (14)

• Many-Body Physics with Ultracold Gases
• The physics of exceptional points
• Efficient Light Funneling based on the non-Hermitian Skin Effect
• Single-Spin Addressing in an Atomic Mott Insulator
• Topological phases in the non-Hermitian Su-Schrieffer-Heeger model
• Topological Transition in a Non-Hermitian Quantum Walk
• Modeling disorder in graphene
• Flat Band in Disorder Driven Non-Hermitian Weyl Semimetals
• Two-terminal transport measurements with cold atoms
• Interaction-controlled transport of an ultracold Fermi gas
• Enhanced nonlinear frequency conversion and Purcell enhancement at exceptional points
• Disorder-induced exceptional points and nodal lines in Dirac superconductors
• Dirac Fermions and Possible Weak Antilocalization in LaCuSb${}_2$
• Color-dependent conductance of graphene with adatoms

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• Anomalous Hall effect from a non-Hermitian viewpoint
• Protection of Correlation-Induced Phase Instabilities by Exceptional Susceptibilities
• Tight-binding model with sublattice-asymmetric spin-orbit coupling for square-net nodal line Dirac semimetals
• Laser induced $\mathcal{P}\mathcal{T}$-symmetry breaking in the fluctuations of electronic fluids
• Nodal Spectral Functions Stabilized by Non-Hermitian Topology of Quasiparticles
• Exceptional Luttinger Liquids from sublattice dependent interaction