Berlin 2015 – scientific programme
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 71: Glasses and Glass transition (joint session DY, CPP, DF)
CPP 71.4: Talk
Thursday, March 19, 2015, 15:45–16:00, BH-N 128
The Potential Energy Landscape of microrheologically driven supercooled liquids — •Carsten F. E. Schroer1,2 and Andreas Heuer1,2 — 1Westfälische Wilhelms-Universität, Münster, Germany — 2NRW Graduate School of Chemistry, Münster, Germany
We perform computer simulations of a fragile model glass-former in which a single particle is driven by an external force through the liquid. Thereby, we track the path the system takes through its underlying Potential Energy Landscape (PEL) and aim for understanding how this is altered by the external field[1,2] and how the altering is related to the nonlinear responses of dynamic quantities.
In the PEL approach, the dynamics of undriven (strong and fragile) glass formers have found to be very well described in terms of an improved trap model, the Gaussian Glass Former (GGF)[3]. In this talk we want to demonstrate, how the GGF can be extended to driven supercooled liquids. This enables one to predict typical nonlinear responses like the nonlinear decay of the local friction coefficient as well as highly nontrivial effects like the occurrence of effective temperatures. Within this framework we can quantitatively predict the numerically observed effective temperatures in terms of the kinetics of the force-dependent hopping processes in the PEL. This establishes an intimate relation between the thermodynamics and the kinetics also in the highly non-equilibrium regime.
[1] C. F. E. Schroer, A. Heuer, J. Chem, Phys 138, 12A518 (2013)
[2] C. F. E. Schroer, A. Heuer, Phys. Rev. Lett 110, 067801 (2013)
[3] A. Heuer, J. Phys.: Condens. Matter 20, 373101 (2008)