Quantum corrections to the magnetoconductivity of surface states in three-dimensional topological insulators

TL;DR

This paper extends the theory of quantum conductance corrections to symplectic systems like topological insulators and experimentally investigates how high-order quantum effects significantly modify magnetoconductivity, revealing complex electronic interactions.

Contribution

It introduces a theoretical framework for high-order quantum corrections in symplectic electron systems and experimentally demonstrates their impact on magnetoconductivity in topological insulator surface states.

Findings

Second-order interference enhances magnetoconductivity

Electron-electron interactions significantly modify MC

MC behavior differs from orthogonal symmetry systems

Abstract

The interplay between quantum interference, electron-electron interaction (EEI), and disorder is one of the central themes of condensed matter physics. Such interplay can cause high-order magnetoconductance (MC) corrections in semiconductors with weak spin-orbit coupling (SOC). However, it remains unexplored how the magnetotransport properties are modified by the high-order quantum corrections in the electron systems of symplectic symmetry class, which include topological insulators (TIs), Weyl semimetals, graphene with negligible intervalley scattering, and semiconductors with strong SOC. Here, we extend the theory of quantum conductance corrections to two-dimensional electron systems with the symplectic symmetry, and study experimentally such physics with dual-gated TI devices in which the transport is dominated by highly tunable surface states. We find that the MC can be enhanced significantly by the second-order interference and the EEI effects, in contrast to suppression of MC for the systems with orthogonal symmetry. Our work reveals that detailed MC analysis can provide deep insights into the complex electronic processes in TIs, such as the screening and dephasing effects of localized charge puddles, as well as the related particle-hole asymmetry.