Photocontrollable Mixed-Valent States in Platinum-Halide Ladder Compounds

Employing a two-orbital extended Peierls–Hubbard model, we demonstrate the photomanipulation of mixed-valent states in platinum-halide ladder compounds. There are two types of interchain valence arrangements, namely in-phase and out-of-phase types. The conversion of the in-phase structure to the out-of-phase structure is induced by photoirradiation, which is accelerated with increasing light intensity, while the reverse process hardly occurs. The out-of-phase arrangement is highly stabilized in the photoexcited states by the interchain electron transfer.