Dresden 2009 – wissenschaftliches Programm

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BP: Fachverband Biologische Physik

BP 16: Stochastic Processes

BP 16.2: Vortrag

Mittwoch, 25. März 2009, 16:15–16:30, ZEU 260

Optimal protocols in Stochastic Thermodynamics — •Tim Schmiedl¹, Alex Gomez-Marin², and Udo Seifert¹ — ¹II. Institut für Theoretische Physik, Universität Stuttgart, 70550 Stuttgart, Germany — ²Facultat de Fisica, Universitat de Barcelona, Diagonal 647, 08028 Barcelona, Spain

For systems in an externally controllable time-dependent potential, the optimal protocol minimizes the mean work spent in a finite-time transition between two given equilibrium states. We consider three different types of dynamics: overdamped Langevin dynamics, underdamped Langevin dynamics, and purely Hamiltonian dynamics. Surprisingly, the optimal protocol involves jumps for overdamped Langevin dynamics and even delta-type singularities for underdamped Langevin dynamics. These optimal protocols significantly improve free energy calculations via the Jarzynski equality.

For purely Hamiltonian dynamics and harmonic potentials, we show that the optimal protocol is highly degenerate and that even in the limit of short transition times, the optimal work is given by the adiabatic work which is substantially smaller than the work for an instantaneous jump. We also perform numerical calculations for purely Hamiltonian dynamics in an anharmonic quartic potential.
T. Schmiedl and U. Seifert, Phys. Rev. Lett 98, 108301 (2007)
A. Gomez-Marin, T. Schmiedl, and U. Seifert, J. Chem. Phys. 129, 024114 (2008)