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Updated: May 20, 2026

Generation and Coherent Control of Pulsed Quantum Frequency Combs
Published on: June 8, 2018
Occupation Dynamics of Floquet-Volkov States and Spectral Sum Rule
Xuanxi Cai1, Changhua Bao1, Benshu Fan1,2
1State Key Laboratory of Low Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing 100084, P.R. China.
Abstract:
Time-periodic light fields can dress electronic states in quantum materials, forming Floquet states whose dynamic occupation determines the transient material properties. Here, by using time- and angle-resolved photoemission spectroscopy (TrARPES), we reveal the transient occupation of Floquet-Volkov states in two semiconductors, black phosphorus and MoSe2. While the occupation of the light-induced sidebands, directly reflected by TrARPES spectral weight, strongly depends on the driving field, we find that the total spectral weight obtained by summing up all sidebands is conserved upon below-gap driving. Our work provides critical insights into the Floquet population dynamics, which are essential for the light-field tailoring of transient material properties.
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