Nonlocal transport near the charge neutrality point in a two-dimensional electron-hole system

TL;DR

This paper investigates nonlocal resistance in a 20 nm HgTe quantum well with electron-hole coexistence, revealing large nonlocal responses near the charge neutrality point under magnetic fields, linked to edge state transport similar to quantum spin Hall effects.

Contribution

It demonstrates the presence of nonlocal resistance linked to edge states in a HgTe quantum well, extending understanding of topological transport phenomena under magnetic fields.

Findings

Large nonlocal resistance observed near CNP under magnetic field

Edge state transport via counter propagating chiral modes identified

Similarity to quantum spin Hall effect and graphene at Landau level f0=0

Abstract

Nonlocal resistance is studied in a two-dimensional system with a simultaneous presence of electrons and holes in a 20 nm HgTe quantum well. A large nonlocal electric response is found near the charge neutrality point (CNP) in the presence of a perpendicular magnetic field. We attribute the observed nonlocality to the edge state transport via counter propagating chiral modes similar to the quantum spin Hall effect at zero magnetic field and graphene near Landau filling factor $\nu=0$