Gate-tuned quantum Hall states in Dirac semimetal (Cd1-xZnx)3As2

TL;DR

This study demonstrates the control of quantum Hall states in Dirac semimetal thin films through carrier density tuning via chemical doping and electrostatic gating, revealing Landau level formation and paving the way for exploring Dirac point physics.

Contribution

It introduces a method to tune carrier density in Dirac semimetal thin films, enabling the observation of quantum Hall states and Landau levels across a wide range of densities.

Findings

Carrier density can be effectively controlled using Zn doping and gating.

Quantum Hall states are observed with Landau level formation.

The results facilitate exploration of Dirac point physics.

Abstract

The recent discovery of topological Dirac semimetals (DSM) has provoked intense curiosity not only on Weyl physics in solids, but also on topological phase transitions originating from DSM. One example is controlling the dimensionality to realize two-dimensional quantum phases such as quantum Hall and quantum spin Hall states. For investigating these phases, the Fermi level is a key controlling parameter. From this perspective, we report here the carrier-density control of quantum Hall states realized in thin films of DSM Cd3As2. Chemical doping of Zn combined with electrostatic gating has enabled us to tune the carrier density over a wide range and continuously even across the charge neutrality point. Comprehensive analyses of the gate-tuned quantum transport have revealed Landau level formation from linearly dispersed sub-bands and its contribution to the quantum Hall states. Our achievements pave the way also for investigating the low energy physics near the Dirac points of DSM.