Dynamical properties of photoexcited states are theoretically studied in a one-dimensional Mott insulator dimerized by the spin-Peierls instability. Numerical calculations combined with a perturbative analysis have revealed that the lowest photoexcited state without nearest-neighbor interaction corresponds to an interdimer charge transfer excitation that belongs to dispersive excitations. This excited state destabilizes the dimerized phase, leading to a photoinduced inverse spin-Peierls transition. We discuss the purely electronic origin of midgap states that are observed in a latest photoexcitation experiment of an organic spin-Peierls compound, K-TCNQ (potassium-tetracyanoquinodimethane).
@article{arxiv.cond-mat/0609186,
title = {Dynamics of photoexcited states in one-dimensional dimerized Mott insulators},
author = {Nobuya Maeshima and Kenji Yonemitsu},
journal= {arXiv preprint arXiv:cond-mat/0609186},
year = {2009}
}
Comments
13 pages, 13 figures, accepted for publication in PRB