Are glasses hot ?
Condensed Matter lunchtime seminar
Are glasses hot ?
- Event time: 1:00pm
- Event date: 5th November 2007
- Speaker: Dr Tiffany Wood (School of Physics & Astronomy, University of Edinburgh)
- Location: Room 2511, James Clerk Maxwell Building (JCMB) James Clerk Maxwell Building Peter Guthrie Tait Road Edinburgh EH9 3FD GB
Event details
By applying the Fluctuation Dissipation Theorem to glasses, theorists
(L.F. Cugliandolo, PRE, 55, 3898 (1997); A. Crisanti, J.Phys.A, 36, R181 (2003)) predicted
that the dynamical fluctuations of a glass can
be characterized by a non-equilibrium temperature. I will present
details of an experiment carried out to measure the temperature of a
colloidal glass. A micron-sized bead held within the harmonic
potential of an optical tweezer forms a microscopic thermometer such
that a temperature can be determined by applying the equipartition
principle. The thermal motion of a tracer particle suspended in a
colloidal material was monitored as the material transformed from a
viscous liquid into an elastic glass. Measurements will be discussed
in terms of the system dynamics, growth of heterogeneities and the
nature of coupling between the probe and the medium. Results confirm
the theoretical predictions of an elevated effective temperature in an
aging glass.
See: Greinert N., Wood T.A., Bartlett P., Physical Review Letters, 97, 265702, 2006.
See: Greinert N., Wood T.A., Bartlett P., Physical Review Letters, 97, 265702, 2006.
About Condensed Matter lunchtime seminars
This is a weekly series of informal talks given primarily by members of the institute of condensed matter and complex systems, but is also open to members of other groups and external visitors. The aim of the series is to promote discussion and learning of various topics at a level suitable to the broad background of the group. Everyone is welcome to attend..