title: Low temperature spectral dynamics of single molecules in ultrathin polymer films.
abstract: We studied the spectral dynamics of single fluorescent dye molecules embedded in ultrathin films (5 - 100 nm) of the amorphous polymer polyisobutylene at cryogenic temperatures and its variation with film thickness. Noticeable portion of molecules in the ensemble shows a behavior which is inconsistent with the standard tunneling model: Their spectral lines are subject to irreversible spectral jumps, continuous shifting, and abrupt chaotic changes of the linewidth or jumping rate. In films thinner than 100 nm, the occurrence of "non-standard" spectral behavior increases with decreasing sample thickness at fixed excitation intensity. In addition, it also increases with laser intensity.
authors.affiliation: Institute for Spectroscopy, RAS, Troitsk, Moscow Region 142190, Russia.
authors.forename: Yaroslav I
authors.initials: YI
authors.lastname: Sobolev
authors.affiliation: Institute for Spectroscopy, RAS, Troitsk, Moscow Region 142190, Russia.
authors.forename: Andrei V
authors.initials: AV
authors.lastname: Naumov
authors.affiliation: Institute for Spectroscopy, RAS, Troitsk, Moscow Region 142190, Russia.
authors.forename: Yuri G
authors.initials: YG
authors.lastname: Vainer
authors.affiliation: Institute of Physics and BIMF, University of Bayreuth, 95440 Bayreuth, Germany.
authors.forename: Lothar
authors.initials: L
authors.lastname: Kador