Abstract
Charge dynamics in one-dimensional (1D) Mott insulators was investigated by femtosecond pump-probe absorption spectroscopy on . An irradiation of a femtosecond laser pulse gives rise to a Drude-like response due to the nature of spin-charge separation characteristic of 1D Mott insulators. The photoinduced metallic state decays with ∼30 fs, and photocarriers are localized as polarons via charge-phonon coupling which produce a broad midgap absorption. Calculations with the extended Hubbard-Holstein model suggest that the peak structure of the midgap absorption is a magnon sideband of the polaron absorption. This demonstrates that charge-spin coupling becomes effective via charge-phonon coupling in polarons.
- Received 2 December 2014
- Revised 5 February 2015
DOI:https://doi.org/10.1103/PhysRevB.91.081114
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