An intense light field can dress both Bloch electrons inside crystals and photo-emitted free electrons in the vacuum, dubbed 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 an 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.

Close

PrevNext

View figure in article

• Electronic structure
• Floquet systems
• Time & angle resolved photoemission spectroscopy