High-Harmonic Spin and Charge Pumping in Altermagnets

TL;DR

This paper demonstrates that altermagnets intrinsically support high-harmonic spin and charge pumping driven by magnetic dynamics, surpassing traditional systems and offering potential for efficient THz emitters and nonlinear spintronics.

Contribution

It reveals the unique nonlinear spin and charge pumping capabilities of altermagnets driven by magnetic dynamics, without needing additional spin-orbit coupling.

Findings

Emission of hundreds of harmonics with large amplitudes

Altermagnets support high-harmonic pumping intrinsically

Potential for efficient THz emitters and nonlinear devices

Abstract

We report the emergence of highly nonlinear spin and charge pumping in an altermagnetic system driven by magnetic dynamics. The non-relativistic spin-momentum coupling inherent to altermagnets (AMs) generates a giant momentum dependent spin splitting, leading to strong spin-flip scattering in the presence of a precessing magnetic order driving the altermagnetic system out of equilibrium. Our simulations reveal the emission of hundreds of harmonics under realistic conditions, with amplitudes far exceeding those obtained in light-driven schemes. Notably, in contrast to ferromagnetic and conventional antiferromagnetic systems, where nonlinear emission typically requires additional spin-orbit coupling, AMs intrinsically support high-harmonic spin and charge pumping. These results identify altermagnetic systems as a promising platform for efficient THz emitters and highly nonlinear spintronic devices.