Using Altermagnets for Straintronics Applications

Altermagnets [1] are predicted to exhibit a linear magnetization in response to an applied lattice strain, a phenomenon known as piezomagnetism. To date, piezomagnetic phenomena on altermagnets have largely focused on strain-induced changes in the static magnetization. Meanwhile, because of piezomagnetism, strain should also strongly modify the magnetic excitation spectrum of altermagnets, a little explored effect that, if realized experimentally, would provide a powerful means of tuning and controlling magnetic properties of altermagnets. Moreover, besides piezomagnetism, in certain altermagnets the lattice and magnetic collective modes hybridize. One example is the mixing of acoustic phonons and magnons, giving rise to a hybrid collective excitation known as a (para)magnon–polaron [2].

 

For this project, we will use electron, x-ray, and neutron scattering, combined with phenomenological modeling, to probe the collective excitations of altermagnetic materials under applied strain and magnetic fields. Our experiments will focus on promising candidate altermagnets, like the rutiles MnF2. Using a precision strain cell and applied magnetic fields, we will investigate the evolution of structural and magnetic Bragg reflections as well as the mixing of phonon and magnon excitations. These studies will establish an understanding of piezomagnetic-related phenomena and a foundation for engineering strain landscapes that enable tailored magnetic functionalities, with potential applications in spintronics.