Participating group members: |
Peter Reimann, Mykhaylo Evstigneev, Sebastian Getfert |

Main cooperation partners: |
Roger Filliger, Clemens Bechinger, Peter Hänggi, Jörg Lehmann, Peter Talkner |

Along the general lines of Kramers reaction rate theory in far from equilibrium systems, three main directions are pursued.

(i) Escape/decay in the presence of randomly fluctuating potential-barriers, of great interest for instance in the context of complex biochemical reactions and transport processes.

(ii) Thermally activated escape over periodically oscillating potential-barriers, a basic scenario in a variety of driven experimental systems.

(iii) Escape rate theory for systems in discrete time. The methodological framework are extensions of path-integral and WKB-type methods in the spirit of a singular perturbation theory for weak noise both for time-continuous and time-discrete non-linear dynamical systems.

These general methods also find applications in our projects on
ratchet effects,
friction phenomena on the nanometer scale,
dynamic force spectroscopy on single biomolecules,
stochastic resonance,
nonlinear dynamics and chaos.
The quantum mechanical counterpart of this research represents the project on
open quantum systems.

Main publications on fluctuating and oscillating barriers:

P. Reimann

*Thermally Driven Escape with Fluctuating Potentials: A new
Type of Resonant Activation*

Phys. Rev. Lett. **74**, 4576 (1995)

P. Reimann and P. Hänggi

*Surmounting Fluctuating Barriers: Basic Concepts and Results*

p. 127 in "Stochastic Dynamics",
Lecture Notes in Physics, Vol. 484

edited by L. Schimansky-Geier and T. Pöschel,
Springer, Berlin 1997

J. Lehmann, P. Reimann, and P. Hänggi

*Surmounting Oscillating Barriers*

Phys. Rev. Lett. **84**, 1639 (2000)

J. Lehmann, P. Reimann, and P. Hänggi

*Activated escape over oscillating barriers: The case of many dimensions*

phys. stat. sol. (b) **237**, 53 (2003)

M. Evstigneev and P. Reimann

*Probability densities of periodically driven noisy systems:
An approximation scheme incorporating linear-response and adiabatic theory*

Phys. Rev. E **72**, 045101(R) (2005)

S. Bleil, P. Reimann, and C. Bechinger

* Directing Brownian motion by oscillating barriers*

Phys. Rev. E **75**, 031117 (2007)

S. Getfert and P. Reimann

*Suppression of thermally activated escape by heating *

Phys. Rev. E **80**, 030101(R) (2010)

Main publications on path-integral- and WKB-methods:

P. Reimann

*Thermally Activated Escape with Potential Fluctuations driven
by an Ornstein-Uhlenbeck Process*

Phys. Rev. E **52**, 1579 (1995)

P. Reimann and T. C. Elston

*Kramers Rate for Thermal plus Dichotomous Noise applied to Ratchets*

Phys. Rev. Lett. **77**, 5328 (1996)

B. Lindner, L. Schimansky-Geier, P. Reimann, P. Hänggi, and M. Nagaoka

*Inertia Ratchets: A Numerical Study Versus Theory*

Phys. Rev. E. **59**, 1417 (1999)

J. Lehmann, P. Reimann, and P. Hänggi

*Surmounting Oscillating Barriers:
Path-integral Approach for Weak
Noise*

Phys. Rev. E **62**, 6282 (2000)

R. Filliger and P. Reimann

*Kramers escape rate for a charged particle in a magnetic field*

Europhys. Lett. **77**, 30008 (2007)

S. Getfert and P. Reimann

*Thermally activated escape far from equilibrium: A unified path-integral approach*

Chem. Phys. **375**, 386 (2010)

Main publications on systems in discrete time:

P. Reimann and P. Talkner

*Invariant Densities for Noisy Maps*

Phys. Rev. A **44**, 6348 (1991)

P. Reimann, R. Müller, and P. Talkner

*Decay of Metastable States with Discrete Dynamics*

Phys. Rev. E **49**, 3670 (1994)

P. Reimann and P. Talkner

*Escape Rates for Noisy Maps*

Phys. Rev. E **51**, 4105 (1995)

P. Reimann and E. Lootens

*Escape Rates for Noisy Maps with Anomalous Prefactors*

Europhys. Lett. **34**, 1 (1996)

*Last modified on 2010-11-03*