Regensburg 2007 – wissenschaftliches Programm

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DY: Fachverband Dynamik und Statistische Physik

DY 8: Quantum dynamics, decoherence and quantum information

DY 8.5: Vortrag

Montag, 26. März 2007, 17:15–17:30, H2

A Boltzmann equation approach to transport in finite modular quantum systems — •Mehmet Kadiroglu and Jochen Gemmer — Departement of Physics, University of Osnabrück, D-49069

We investigate the transport behaviour of finite quantum systems based on a Boltzmann equation [1] (BE). To make the BE applicable for our quantum systems we consider quasiparticles which are essentially the current eigenmodes of the system. We propose to identify the classical particle density in the BE with the quantum mechanical occupation numbers of the current eigenstates. It is demonstrated analytically and numerically by solving the time dependent Schrödinger equation that this concept is justifiable and that the dynamics of the quantum mechanical occupation numbers are indeed well described by an appropriate linear BE. Furthermore we determine the diffusion coefficient of a diffusive solution of the linear BE which is in accordance with results of previous works [2]. An ab initio numerical analysis of the full dynamics of the quantum system shows that it indeed exhibits diffusive behaviour controlled by this diffusion constant under certain conditions.

1 L. Boltzmann, Lectures on Gas Theory, University of California Press, Los Angeles, (1964)
2 M. Michel, J. Gemmer, G. Mahler, Phys. Rev. Lett., 95, 180602, (2005)