Dresden 2006 – scientific programme

Parts | Days | Selection | Search | Downloads | Help

CPP: Chemische Physik und Polymerphysik

CPP 25: POSTER Electronic Structure and Spectroscopy

CPP 25.5: Poster

Thursday, March 30, 2006, 17:00–19:00, P2

Hierarchical and approximate quantum master equations based on a decomposition of the spectral density applied to electron injection into a DNA base pair — •G.-Q. Li, M. Schröder, M. Schreiber, and U. Kleinekathöfer — Institut für Physik, Technische Universität Chemnitz, 09107 Chemnitz

The relaxation process of a system of one and of two interacting harmonic oscillators coupled to a thermal heat bath is studied. On short time scales memory effects play an important role for the relaxation behavior of the systems density matrix. For the description of such dynamical effects Meier and Tannor proposed a time-nonlocal scheme [1] based on second-order perturbation theory. In their scheme a set of auxiliary density matrices enters the quantum master equation and gives rise to the memory effects [2]. In our work we will use a modified and numerically less expensive version of recently proposed hierarchical methods [3,4] for exactly solving the quantum master equation of the reduced systems density matrix. This method can be shown to be identical with the scheme of Meier and Tannor to second order in the system-bath coupling but can be easily extended to higher orders. The different levels of theories are tested for a damped harmonic oscillator and for two coupled oscillators mimicking the electron injection from a donor into a DNA base pair.

[1] C. Meier, D. Tannor, J. Chem. Phys. 111 3365, (1999).

[2] U. Kleinekathöfer, J. Chem. Phys. 121, 2505 (2004).

[3] Y. Yan, F. Yang, Y. Liu, J. Shao, Chem. Phys. Lett. 395 216 (2004).

[4] R.-X. Xu et al, J. Chem. Phys. 122 041103 (2005).