title: Brownian Motion of Molecular Probes in Supercooled Liquids.
abstract: When a supercooled liquid approaches glass transition, viscous flow slows down greatly, but often the Brownian motion of a molecular probe in the host liquid does not slow down as much, causing the Stokes-Einstein relation to fail by orders of magnitude. Here we formulate a theory that relates the Brownian motion of the probe to two concurrent processes in the host liquid: viscous flow and molecular hopping. Molecular hopping prevails over viscous flow when the probe is small and the temperature is low. Our theory generalizes the Stokes-Einstein relation and fits the experimental data remarkably well.
authors.affiliation: School of Engineering and Applied Sciences, Kavli Institute for Bionano Science and Technology, Harvard University, Cambridge, Massachusetts 02138, USA.
authors.forename: Qihan
authors.initials: Q
authors.lastname: Liu
authors.affiliation: School of Engineering and Applied Sciences, Kavli Institute for Bionano Science and Technology, Harvard University, Cambridge, Massachusetts 02138, USA.|School of Aerospace, Tsinghua University, Beijing 100084, People's Republic of China.
authors.forename: Shicheng
authors.initials: S
authors.lastname: Huang
authors.affiliation: School of Engineering and Applied Sciences, Kavli Institute for Bionano Science and Technology, Harvard University, Cambridge, Massachusetts 02138, USA.
authors.forename: Zhigang
authors.initials: Z
authors.lastname: Suo