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Updated: Sep 17, 2025

Direct Imaging of Laser-driven Ultrafast Molecular Rotation
Published on: February 4, 2017
Electron Dynamics Induced by Circularly Polarized Laser Pulses in Im-3m H3S in the Superconducting Pressure Regime
Lizhi Tang1, Genwei Hong1, Tianlv Xu1
1Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research and Key Laboratory of Resource National and Local Joint Engineering Laboratory for New Petro-Chemical Materials and Fine Utilization of Resources, College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha, Hunan, China.
Abstract:
We investigated crystalline Im-3m H3S at 200 GPa, a pressure regime where H3S is generally considered to be an exotic superconductor. Simulated circularly polarized 10 femtosecond (fs) laser pulses were applied and we quantified the effects on the electron dynamics during the application of "pump" and candidate "probe" laser pulses to discover optimal "probe" laser pulses. This is undertaken for the first application of Next Generation Quantum Theory of Atoms in Molecules (NG-QTAIM) using the Hessian of the "spin-up" and "spin-down" contributions to the total electronic charge density ρ(r). The optimal "probe" pulse was found to possess a peak electric field E = 10.0 × 10-4 a.u. compared with the "pump" pulse of E = 200.0 × 10-4 a.u. Separately considering the spin-up and spin-down contributions doubles the values of the chirality-helicity Chelicity function relative to that of the total charge density contribution for the H-H bonding for the application of the "pump" laser pulse. Within the NG-QTAIM interpretation, a combination of highly responsive and coherent behaviors is associated with superconductivity. These behaviors were discovered from the very high values of the Chelicity function, near-linear scaling of the bond-flexing F and bond-chirality C values with peak E-field and all instances of the H-H bonding possessing R electronic chirality assignments. The "pump" pulse was found to magnify the effects associated with superconductivity within the NG-QTAIM interpretation. Future applications are discussed including chiral spin selective phenomena and exotic high temperature superconductivity where phonons do not play a significant role.
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