title: Ultrafast optical switching from an ionic to a neutral state in tetrathiafulvalene-p-chloranil (TTF-CA) observed in femtosecond reflection spectroscopy.
abstract: Ultrafast optical switching from an ionic ( I) to a neutral ( N) state in TTF-CA was observed in femtosecond reflection spectroscopy. Charge transfer excitation in the I phase produces N donor ( D0) acceptor ( A0) strings within 2 ps. These initial N states decay with a lifetime of 300 ps at 4 K, but rather multiply leading to macroscopic I-N conversion within 20 ps at 77 K just below the N-I transition temperature T(NI). Near T(NI), we also found the evidence for the coherent motion of the macroscopic N-I domain boundary with a period of 85 ps.
authors.affiliation: Correlated Electron Research Center (CERC), National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba 305-0046, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Iwai
authors.forename: S
authors.initials: S
authors.lastname: Tanaka
authors.forename: K
authors.initials: K
authors.lastname: Fujinuma
authors.forename: H
authors.initials: H
authors.lastname: Kishida
authors.forename: H
authors.initials: H
authors.lastname: Okamoto
authors.forename: Y
authors.initials: Y
authors.lastname: Tokura