High harmonic generation from the magnetic side

In quantum optics we often shine Laser on nonlinear media to induce highly nonlinear dynamics from the strong interaction between light and matter. In our recently proposed approach [1], we rather suggest the use of magnetic dynamics instead, to generate higher harmonics of the driving frequency ω. By employing an adiabatic framework, we reveal that the interaction between magnetic dynamics and spin-orbit coupled carriers leads to highly nonlinear energy dispersion [2]. This nonlinear behavior directly reflects the high-frequency excitations responsible for non-equilibrium transport phenomena. Our analysis highlights that the dynamics of instantaneous energy levels encode key signatures of high harmonic generation (HHG), offering a clear and simplified understanding of the effect. Furthermore, we unveil a distinct scaling law of magnetically driven systems in terms of the driving frequency [3]. Namely, we find a linear scaling law of the harmonics cutoff in terms of ω^-1, in contrast to the optical driving, where the scaling appears to be linear in ω^-3 [4].

[1] Ly et al 2022 PRB 105 L180415 (2022)

[2] Ly JPCM 35 125802 (2023)

[3] Ly JPCM (2025)

[4] Krause et al PRL 68 3535–3538 (1992)