title: Quasidegenerate self-trapping in one-dimensional charge transfer exciton.
abstract: The self-trapping by the nondiagonal particle-phonon interaction between two quasidegenerate energy levels of the excitonic system is studied. We propose this is realized in the charge-transfer exciton, where the directions of the polarization give the quasidegeneracy. It is shown that this mechanism, unlike the conventional diagonal one, allows a coexistence and resonance of the free and self-trapped states even in one-dimensional systems and a quantitative theory for the optical properties (light absorption and time-resolved luminescence) of the resonating states is presented. This theory gives a consistent resolution for the long-standing puzzles in quasi-one-dimensional compound A-PMDA.
authors.affiliation: Correlated Electron Research Center, Tsukuba 305-0046, Japan.
authors.forename: A S
authors.initials: AS
authors.lastname: Mishchenko
authors.forename: N
authors.initials: N
authors.lastname: Nagaosa