title: Light-induced giant softening of network glasses observed near the mean-field rigidity transition.
abstract: The longitudinal acoustic (LA) mode of bulk GexSe1-x glasses is examined in Brillouin scattering (BS) over the 0.15<x<1/3 range using near band-gap radiation (lambda=647.1 nm). The LA-mode frequency (nu(LA)) softens with increasing laser power in an athermal and reversible manner by nearly 30% (=Delta nu(LA)/nu(LA)) near x=x(c)=0.19(1) or mean coordination number, r(c)=2+2x(c)=2.38(2), close to the mean-field rigidity percolation transition (r(t)=2.40). BS is a bulk probe of elasticity, and photosoftening is maximized here when network stress is minimized near the elastic phase transition.
authors.affiliation: Department of Physics, The Ohio State University, Columbus, Ohio 43210, USA.
authors.forename: J
authors.initials: J
authors.lastname: Gump
authors.forename: I
authors.initials: I
authors.lastname: Finkler
authors.forename: H
authors.initials: H
authors.lastname: Xia
authors.forename: R
authors.initials: R
authors.lastname: Sooryakumar
authors.forename: W J
authors.initials: WJ
authors.lastname: Bresser
authors.forename: P
authors.initials: P
authors.lastname: Boolchand