Femtosecond Dynamics, Photoexcitation and ESR Spectra of MX Chain Solids

摘要

Nonlinear adiabatic dynamics and ESR spectra associated with nonlinearexcitations in MX chain (M = Pt, X = CL,Br,I) materials are numerically studied within a discrete, 3/4-filled, two-band, tight-binding extended Peierls-Hubbard model. Both Hartree-Fock (HF) adiabatic molecular relaxation and molecular dynamics techniques are employed to investigate the time evolution of solitons, polarons, bipolarons in charge-density-wave (CDW) ground state materials. The time evolution of excitons, defect pairs and/or breathers is studied subsequent to photoexcitation. The ESR spectra associated with the resulting spin carrying nonlinear excitations such as neutral solitons, triplet excitons as well as electron and hole polarons are then calculated within the above model. The superhyperfine structure in the ESR spectra is attributed to a small spin density present on the halogen sublattice.