Hannover 2010 – wissenschaftliches Programm

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A: Fachverband Atomphysik

A 8: Poster I

A 8.17: Poster

Dienstag, 9. März 2010, 16:30–19:00, Lichthof

Efficient grid-based nonequilibrium Green’s function calculations: I. General method and applications to atoms and molecules — •Karsten Balzer and Michael Bonitz — ITAP, Christian-Albrechts-Universität Kiel, Leibnizstr. 15, 24098 Kiel

For strongly inhomogeneous quantum systems, the use of finite elements (FE) in combination with the discrete variable representation (DVR) [1,2] allows for an optimal and flexible representation of the nonequilibrium Green’s function (NEGF) in coordinate space [3]. In contrast to a general basis approach, the complementary features of the FE-DVR lead (i) to (semi-)analytic matrix elements of the kinetic, potential and interaction energy operators, (ii) to drastic simplifications of the self-energies and, in turn, (iii) to an essential speedup in the computation of the NEGF.

As atomic and molecular examples, we compute, in Hartree-Fock and second Born approximation, the equilibrium properties of the helium atom, the hydrogen molecule, and lithium hydride modeled in one spatial dimension [3]. The results comprise the self-consistent ground-state/binding energies, densities and bond-lengths which are compared with the solution of the few-particle time-dependent Schrödinger equation.

[1] T.N. Rescigno, and C.W. McCurdy, Phys. Rev. A 62, 032706 (2000). [2] B.I. Schneider, L.A. Collins, and S.X. Hu, Phys. Rev. E 73, 036708 (2006). [3] K. Balzer, S. Bauch, and M. Bonitz, arXiv:0910.5458, submitted to Phys. Rev. A (2009).