Integer quantum Hall effect and enhanced g-factor in quantum confined Cd3As2 films

TL;DR

This study explores the integer quantum Hall effect in quantum confined Cd3As2 films, revealing enhanced g-factors and spin degeneracy lifting, with implications for understanding topological states in thin films.

Contribution

It demonstrates the observation of integer quantum Hall states and spin degeneracy lifting in Cd3As2 films, and attributes the enhanced g-factor to quantum confinement effects and subband interactions.

Findings

Integer quantum Hall effect observed at various filling factors.

Lifting of Landau level spin degeneracy at ν=3 with increased confinement.

Enhanced g-factor attributed to quantum confinement and subband effects.

Abstract

We investigate the integer quantum Hall effect in Cd3As2 thin films under conditions of strong to moderate quantum confinement (thicknesses of 10 nm, 12 nm, 15 nm). In all the films, we observe the integer quantum Hall effect in the spin-polarized lowest Landau level (filling factor {\nu} = 1) and at spin-degenerate higher index Landau levels with even filling factors ({\nu} = 2,4,6). With increasing quantum confinement, we also observe a lifting of the Landau level spin degeneracy at {\nu} = 3, manifest as the emergence of an anomaly in the longitudinal and Hall resistivity. Tight-binding calculations show that the enhanced g-factor likely arises from a combination of quantum confinement and corrections from nearby subbands. We also comment on the magnetic field induced transition from an insulator to a quantum Hall liquid when the chemical potential is near the charge neutrality point.