Entanglement and nonclassicality of harmonic modes in solid-state high-harmonic generation
Phys. Rev. A 114, 033107 – Published 11 September, 2026
DOI: https://doi.org/10.1103/k3rf-bhbc
Abstract
We investigate the quantum optical properties of high-harmonic generation in semiconductors, focusing on the nonclassicality and entanglement of harmonic modes. By conditioning the emitted field on harmonic excitation, we obtain conditional harmonic states that exhibit pronounced nonclassical features in the plateau region. For harmonic photon energies above the minimum energy gap, the conditional states associated with interband transitions exhibit significantly stronger entanglement and nonclassicality than those associated with intraband processes. These results reveal how microscopic interband and intraband electron dynamics determine the quantum properties of conditional harmonic states, providing insight into the microscopic origin of nonclassical features in high-harmonic generation and highlighting the potential for generating nonclassical extreme-ultraviolet light sources.
