Strain continuously rotates the N\'eel vector in altermagnetic MnTe

TL;DR

This study demonstrates that applied strain in altermagnetic MnTe can continuously rotate the Ne9el vector, effectively tuning the material's symmetry and properties, with implications for spintronic device design.

Contribution

It reveals that strain primarily causes continuous rotation of the Ne9el vector in MnTe, providing new insights into controlling altermagnetic properties.

Findings

Strain induces continuous rotation of the Ne9el vector in MnTe.

Built-in strain can pin the Ne9el vector into textures over millimeter scales.

The Ne9el vector orientation can be used as a tunable degree of freedom in spintronics.

Abstract

Altermagnetism has recently emerged as a distinct class of collinear antiferromagnets that break time-reversal symmetry, exhibiting a host of novel properties. Applied strain has attracted particular attention as a key tuning parameter for altermagnets. Although several experimental studies have demonstrated the preparation of single-domain states through a combination of applied strain and magnetic field, the route to such states remains unclear. Here, we use magneto-optical measurements on single crystals of MnTe under applied strain to show that, in contrast to previous reports, strain acts primarily to rotate the N\'eel vector L continuously. Since the orientation of L determines the magnetic point group symmetry, this continuous rotation effectively tunes the symmetry and its associated physical properties. Furthermore, we demonstrate that built-in strain in free-standing crystals is sufficient to pin L into continuous textures over millimeter length scales. Together, these results provide guidance for future device design and open the door to leveraging the N\'eel vector orientation as a tunable degree of freedom in spintronic applications.