Leveraging strain-induced staggered Dzyaloshinskii-Moriya interaction for altermagnetic Néel vector control

Abstract

Exploiting altermagnets for spintronic applications inevitably requires their growth on a substrate as thin films, where strain is always present. Here we show that the strain can induce the staggered Dzyaloshinskii-Moriya interaction (DMI) in a centrosymmetric altermagnet, in which the DMI is expected to be nullified. The strain-induced staggered DMI leads to the emergence of global weak ferromagnetism in the strained altermagnet, which opens up the control of the Néel vector by magnetic fields. A macrospin model describing the evolution of magnetic moments in the strained altermagnet is developed, and the hysteresis behavior of the altermagnetic Néel vector is reproduced. A three-dimensional magnetization model calculation leads to more realistic Néel vector switching fields rather than a two-dimensional model. Our results highlight the crucial role of the strain-induced staggered DMI in altermagnetic thin films.