Magnetophononics: ultrafast spin control through the lattice

TL;DR

This paper demonstrates that intense optical excitation of phonons can rapidly modify magnetic interactions in insulating materials, enabling ultrafast control of spin states through lattice dynamics.

Contribution

It introduces a novel approach to manipulate magnetic states via phonon-induced lattice deformations, combining first-principles and magnetization calculations.

Findings

Phonon excitation at 17 THz alters magnetic exchange interactions.

Nonlinear phononic coupling causes a persistent change in magnetic structure.

Modulation of exchange interactions influences magnetization dynamics.

Abstract

Using a combination of first-principles and magnetization-dynamics calculations, we study the effect of the intense optical excitation of phonons on the magnetic behavior in insulating magnetic materials. Taking the prototypical magnetoelectric \CrO\ as our model system, we show that excitation of a polar mode at 17 THz causes a pronounced modification of the magnetic exchange interactions through a change in the average Cr-Cr distance. In particular, the quasi-static deformation induced by nonlinear phononic coupling yields a structure with a modified magnetic state, which persists for the duration of the phonon excitation. In addition, our time-dependent magnetization dynamics computations show that systematic modulation of the magnetic exchange interaction by the phonon excitation modifies the magnetization dynamics. This temporal modulation of the magnetic exchange interaction strengths using phonons provides a new route to creating non-equilibrium magnetic states and suggests new avenues for fast manipulation of spin arrangements and dynamics.