Shift current from electromagnon excitations in multiferroics

TL;DR

This paper theoretically demonstrates that electromagnons in multiferroics can induce a dc current through the shift current mechanism, linking spin wave excitations to electric current generation.

Contribution

It reveals a novel photoinduced dc current mechanism in multiferroics driven by electromagnon excitations, expanding understanding of spin-charge coupling effects.

Findings

Electromagnons can generate dc current upon photoexcitation.

The shift current mechanism explains the induced dc current.

The shift vector is a key geometric quantity in this process.

Abstract

Electromagnon is the spin wave in multiferroic materials and is known to accompany electric polarization due to the cross correlation between the charge and spin. Here, we theoretically show that the electromagnons also induce dc current upon their photoexcitations. The proposed dc current response originates from the shift current mechanism which is characterized by the so called shift vector, a geometric quantity of the Bloch wavefunctions.