Finite-temperature second harmonic generation in Kitaev magnets

We study electric-field-induced second harmonic generation (SHG) in the Kitaev model. This frustrated magnet hosts a quantum spin liquid, featuring fractionalization terms of mobile Majorana fermion and static ${\mathbb{Z}}_{2}$ flux-vison elementary excitations. show that finite-temperature SHG allows to probe characteristic features both fractional quasiparticle types. In homogeneous flux state at low temperatures, susceptibility displays an oscillatory spectrum, which is set by only fermionic excitations subject temperature-induced Fermi blocking, generic all higher (HHG). intermediate high-temperature range, intrinsic randomness, emerges from thermally excited visons leads drastic changes susceptibility, resulting resonance decoupling over wide range energies. At proliferation crossover, we suggest interpolation between these two temperature regimes. Our results satisfy previously established symmetries for magnets.