Experimental electronic structure of the electronically switchable antiferromagnet, CuMnAs

Tetragonal CuMnAs is a room temperature antiferromagnet with an electrically reorientable Néel vector. We report direct measurements of the electronic structure of single-crystalline thin films using ARPES. We extract Fermi surfaces (FS) and E-k dispersions. After correcting for an unexpected chemical potential shift of -430 meV (hole doping), we find excellent agreement of FS, orbital character, and Fermi velocities between experiment and Density Functional Theory calculations (DFT), using GGA+U with U = 3 eV. We also find 2x1 surface reconstructions in LEED and ARPES. This work underscores the need to control the chemical potential in tetragonal CuMnAs to enable the exploration and exploitation of the topological quantum switching of the Dirac point above the chemical potential in the current samples.