Wurtzite vs rock-salt MnSe epitaxy: electronic and altermagnetic properties

TL;DR

This paper demonstrates that MnSe exhibits altermagnetic properties in the wurtzite phase with high critical temperature, combining ab initio calculations and experimental epitaxy to explore its electronic and magnetic characteristics.

Contribution

It is the first to identify altermagnetic behavior in the wurtzite phase of MnSe and shows how epitaxial growth techniques can control phase formation.

Findings

MnSe exhibits altermagnetic spin-splitting in the wurtzite phase.

High critical temperature of MnSe exceeds room temperature.

Epitaxial growth on GaAs enables phase control of MnSe.

Abstract

Newly discovered altermagnets are magnetic materials exhibiting both compensated magnetic order, similar to antiferromagnets, and simultaneous non-relativistic spin-splitting of the bands, akin to ferromagnets. This characteristic arises from the specific symmetry operations that connect the spin sublattices. In this report, we show with ab initio calculations that the semiconductive MnSe exhibits altermagnetic spin-splitting in the wurtzite phase as well as a critical temperature well above room temperature. It is the first material from such space group identified to possess altermagnetic properties. Furthermore, we demonstrate experimentally through structural characterization techniques that it is possible to obtain thin films of both the intriguing wurtzite phase of MnSe and the more common rock-salt MnSe using molecular beam epitaxy on GaAs substrates. The choice of buffer layers plays a crucial role in determining the resulting phase and consequently extends the array of materials available for the physics of altermagnetism.