2024/12/27 by Wenqing Li, Li, Wenqing, Xiao-Song Zhu +13 · 1 citation
Neuroscience · Physics and Astronomy · #FOS: Physical sciences #Laser-Matter Interactions and Applications #Optics (physics.optics) #Photoreceptor and optogenetics research #Spectroscopy and Quantum Chemical Studies
paper · pdf · doi:10.48550/arxiv.2412.19612
openalex publication_date 2024/12/27 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
We propose a scheme for retrieving the ultrafast valley polarization (VP) dynamics in two-dimensional hexagonal materials via attosecond circular dichroism (CD) transient absorption spectroscopy. This approach builds on the CD transition between the first and higher conduction bands induced by the circularly polarized probe pulses. The population imbalance at nonequivalent valleys in the first conduction band is proportionally mapped onto the difference in absorption coefficients of two probe pulses with opposite helicities, supporting an unprecedented quantitative retrieval of the corresponding VP dynamics with subfemtosecond time resolution. We theoretically demonstrate the scheme for h-BN and MoS2 through ab initio calculations, achieving an accurate retrieval of the VP dynamics, particularly the transient VP switching processes, with a time resolution of 250 as.