Pressure tuning of electronic and magnetic properties in a topological antiferromagnet*

The antiferromagnetic interlayer exchange coupling in MnBi₂Te₄-based magnetic topological insulators gives rise to rich magnetic states as distinguished by their spin configurations. Reversible control of the magnetism and band topology is greatly sought after to access their unexplored quantum states and achieve better control of these states. Mechanical modulations of the lattice structure serve as an effective tuning parameter, which can manipulate the electronic band structures and modify the crystal field splitting, leading to the interplay of magnetic and topological phases. Here, we studied the magnetotransport properties of the MnBi₂Te₄ thin films under hydrostatic pressure. We observed a reversible control of both the magnetic and topological phases by high pressure at different magnetic fields. Our results suggest that pressure allows a tuning of the surface exchange interaction and the Chern insulator state.