Dresden 2011 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 38: Poster Session Transport

TT 38.14: Poster

Mittwoch, 16. März 2011, 14:00–18:00, P3

Extension of the nonequilibrium Green’s funtion towards systems with broken translational invariance — •Steven Achilles¹, Michael Czerner², Christian Heiliger², and Ingrid Mertig¹ — ¹Institute of Physics, Martin Luther University Halle-Wittenberg, D-06099 Halle, Germany — ²I. Physikalisches Institut, Justus Liebig University, D-35392 Giessen, Germany

Electronic structure calculations are nowadays an important tool for investigating and predicting physical effects of new materials on the nanometerscale. In particular, the electronic transport properties under finite bias voltages are of great interest.

To account for systems under bias we extended our Korringa-Kohn-Rostoker Green’s function method [1] to the Keldysh formalism [2]. The method was developed for two different types of geometries, planar junctions [3] and embedded clusters. Both implementations include the self-consistent treatment of systems under external bias using the nonequilibrium density between the chemical potentials of the left and the right lead.

We present ab initio results of voltage drops, the charge relaxation under finite bias voltage and current-voltage characteristics for the two different types of geometries.

[1] R. Zeller, P.H. Dederichs, B. Ujfalussy, L. Szunyogh, and P. Weinberger, Phys. Rev. B 52, 8807 (1995).; P. Zahn, I. Mertig, R. Zeller, and P.H. Dederichs, Mat. Res. Soc. Symp. Proc. 475, 525 (1997).

[2] L.V. Keldysh, Sov. Phys. JETP 20 (4), 1018-1026 (1965).

[3] C. Heiliger et al., J. Appl. Phys. 103, 07A709 (2008).