Regensburg 2016 – wissenschaftliches Programm
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DY: Fachverband Dynamik und Statistische Physik
DY 45: Brownian Motion and Transport
DY 45.3: Vortrag
Mittwoch, 9. März 2016, 17:00–17:15, H46
Quantum-state diffusion approach to the dissipative dynamics of a 1-d double-well system — •Chiara Liverani1, Michael Finnis1,2, and Eva-Maria Graefe3 — 1Department of Physics, Imperial College London — 2Department of Materials, Imperial College London — 3Department of Mathematics, Imperial College London
The generalisation of classical transition rate theory to quantum mechanics is a long-standing problem. A common approach is to interpret Feynman’s isomorphism between a quantum-mechanical particle and a periodic ensemble of harmonically interacting classical particles in a dynamical sense, leading for example to the so-called ring-polymer molecular dynamics (RPMD) method.
Here we investigate a toy model to shed further light on the connection between this type of semiclassical description for the open quantum dynamics and the results based on the quantum master equation. We study the time evolution of a particle in a double-well potential governed by a Lindblad equation, as a quantum analogue of a classical Langevin equation. We use the quantum state diffusion approach, where the evolution of the density operator is modelled by an ensemble average over stochastic Schrödinger equations. We investigate the effects of quantum-mechanical tunnelling and coherence in comparison to the classical dynamics and to that yielded by the RPMD method.