title: Short-Time Beta Relaxation in Glass-Forming Liquids Is Cooperative in Nature.
abstract: Temporal relaxation of density fluctuations in supercooled liquids near the glass transition occurs in multiple steps. Using molecular dynamics simulations for three model glass-forming liquids, we show that the short-time β relaxation is cooperative in nature. Using finite-size scaling analysis, we extract a growing length scale associated with beta relaxation from the observed dependence of the beta relaxation time on the system size. We find, in qualitative agreement with the prediction of the inhomogeneous mode coupling theory, that the temperature dependence of this length scale is the same as that of the length scale that describes the spatial heterogeneity of local dynamics in the long-time α-relaxation regime.
authors.affiliation: Centre for Interdisciplinary Sciences, Tata Institute of Fundamental Research, 21 Brundavan Colony, Narsingi, Hyderabad 500075, India.
authors.forename: Smarajit
authors.initials: S
authors.lastname: Karmakar
authors.affiliation: Centre for Condensed Matter Theory, Department of Physics, Indian Institute of Science, Bangalore 560012, India.|Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore 560064, India.
authors.forename: Chandan
authors.initials: C
authors.lastname: Dasgupta
authors.affiliation: Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore 560064, India.
authors.forename: Srikanth
authors.initials: S
authors.lastname: Sastry