Intense light-field can dress both Bloch electrons inside crystals and photo-emitted free electrons in the vacuum, dubbed as Floquet and Volkov states respectively. These quantum states can further interfere coherently, modulating light-field dressed states. Here, we report experimental evidence of the Floquet-Volkov interference in a semiconductor - black phosphorus. A highly asymmetric modulation of the spectral weight is observed for the Floquet-Volkov states, and such asymmetry can be further controlled by rotating the pump polarization. Our work reveals the quantum interference between different light-field dressed electronic states, providing insights for material engineering on the ultrafast timescale.
@article{arxiv.2502.07357,
title = {Floquet-Volkov interference in a semiconductor},
author = {Changhua Bao and Haoyuan Zhong and Benshu Fan and Xuanxi Cai and Fei Wang and Shaohua Zhou and Tianyun Lin and Hongyun Zhang and Pu Yu and Peizhe Tang and Wenhui Duan and Shuyun Zhou},
journal= {arXiv preprint arXiv:2502.07357},
year = {2025}
}