# Pressure-Tunable Phase Transitions in Atomically Thin Chern Insulator MnBi2Te4

## TL;DR

This study explores how pressure affects the electronic properties of MnBi2Te4, revealing phase transitions between trivial and Chern insulator states.

## Contribution

The paper demonstrates pressure-tunable phase transitions in MnBi2Te4, revealing a Chern insulator state under high magnetic fields.

## Key findings

- Magnetoresistance measurements show a trivial insulator state in the antiferromagnetic phase.
- A Chern insulator state emerges under high magnetic fields.
- Pressure enhances interlayer coupling and reduces the trivial band gap.

## Abstract

Topological insulators lacking time-reversal symmetry
can exhibit
the quantum anomalous Hall effect. Odd-layer thick MnBi2Te4 is a promising platform due to its intrinsic magnetic
nature; however, quantization is rarely observed in it. Our magnetoresistance
measurements in the antiferromagnetic phase indicate, instead of a
quantum anomalous Hall insulator, the presence of a trivial insulator
state likely due to disorder, while in a high magnetic field, a Chern
insulator state appears. From the magnetic field and temperature dependence,
we estimate that the interlayer exchange coupling is enhanced by hydrostatic
pressure while the intralayer coupling is weakened. The trivial band
gap is also reduced, suggesting the role of disorder is weakened upon
compression of the layers.