6533b85cfe1ef96bd12bd64a

RESEARCH PRODUCT

Transport in topological insulators with bulk-surface coupling: Interference corrections and conductance fluctuations

Georg SchwieteTobias MicklitzHristo VelkovG. N. Bremm

subject

PhysicsCondensed matter physicsCondensed Matter - Mesoscale and Nanoscale PhysicsConductanceFOS: Physical sciences02 engineering and technology021001 nanoscience & nanotechnologyThermal conduction01 natural sciencesWeak localizationsymbols.namesakeTopological insulator0103 physical sciencesMesoscale and Nanoscale Physics (cond-mat.mes-hall)symbols010306 general physics0210 nano-technologyHamiltonian (quantum mechanics)

description

Motivated by the experimental difficulty to produce topological insulators (TIs) of the ${\text{Bi}}_{2}{\text{Se}}_{3}$ family with pure surface-state conduction, we study the effect that the bulk can have on the low-temperature transport properties of gated thin TI films. In particular, we focus on interference corrections, namely weak localization (WL) or weak antilocalization (WAL), and conductance fluctuations (CFs) based on an effective low-energy Hamiltonian. Utilizing diagrammatic perturbation theory, we first analyze the bulk and the surface separately and subsequently discuss WL/WAL and CFs when a tunneling-coupling is introduced. We identify the relevant soft diffusion modes of the coupled system and use this insight to make simultaneous predictions for both interference corrections and conductance fluctuations in various parameter regimes. The results strongly suggest that the combined measurement of both quantities can provide an improved understanding of the physics underlying the low-temperature transport processes in thin TI films with bulk-surface coupling.

yearjournalcountryeditionlanguage
2018-12-28
https://dx.doi.org/10.48550/arxiv.1812.11110