High harmonic generation by dynamic Fermi surface nesting
Phys. Rev. B 113, 094415 – Published 9 March, 2026
DOI: https://doi.org/10.1103/wjf4-1zyj
Abstract
We theoretically demonstrate high harmonic generation (HHG) of the ac charge current, in which the emitted current contains integer multiples of the fundamental frequency. By solving the Landau-Lifshitz-Gilbert equation under a GHz ac magnetic field and evaluating the pumped charge current using Brouwer's formula, we find that standing spin waves generate ac charge currents containing exclusively even-order harmonics. Remarkably, the harmonic order exceeds 800 where electron scattering due to the spin waves is resonant, reaching to the THz regime. Our numerical results are explained by a microscopic theory based on spin gauge fields, revealing a mechanism driven solely by interaction between conduction electrons spin and spin waves.
