Occupation Dynamics of Floquet–Volkov States and Spectral Sum Rule
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.
Authors
- Pu Yu (ORCID: https://orcid.org/0000-0002-1897-3826)
- Peizhe Tang
- Wenhui Duan (ORCID: https://orcid.org/0000-0001-9685-2547)
- Tianyun Lin (ORCID: https://orcid.org/0000-0002-4541-7171)
- Benshu Fan (ORCID: https://orcid.org/0000-0003-3845-5855)
- Xuanxi Cai (ORCID: https://orcid.org/0009-0004-6444-9541)
- Changhua Bao (ORCID: https://orcid.org/0000-0002-8706-6541)
- Hongyun Zhang
- Shuyun Zhou (ORCID: https://orcid.org/0000-0002-9841-8610)
- Shaohua Zhou
- Haoyuan Zhong (ORCID: https://orcid.org/0000-0003-0453-3405)
- Fei Wang
Institutions
- Center for Free-Electron Laser Science (DE)
- Max Planck Institute for the Structure and Dynamics of Matter (DE)
- State Key Laboratory of Low-Dimensional Quantum Physics
- Beihang University (CN)
- Tsinghua University (CN)
Publication Details
- Journal
- Nano Letters
- Published
- 2026-05-18
- DOI
- https://doi.org/10.1021/acs.nanolett.6c01340
- Primary Topic
- Spectral Theory in Mathematical Physics
- Type
- article
- Field-Weighted Citation Impact
- 0.00
Funders
- National Natural Science Foundation of China