Berlin 2005 – wissenschaftliches Programm

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MA: Magnetismus

MA 20: Poster:Schichten(1-29),Spintrsp(30-45),Ex-Bias(46-63),Spindyn(64-75),Mikromat.(76-80),Cluster(81-94),Abbv.(95-99),Obflm(100-02),SpElek.(103-09),E-Theo(110-14),Mikromag.(115-16),Spin+PÜ(117-26),Mag.Mat.(127-51),Meth.(152-55),Mol.Mag(156-59),Kondo(160-65

MA 20.110: Poster

Montag, 7. März 2005, 14:00–18:00, Poster TU C

Current-density-functional theory approach to persistent currents and orbital magnetism — •Marc Siegmund and Oleg Pankratov — Lst. für Theoretische Festkörperphysik, Universität Erlangen-Nürnberg, Staudtstr. 7, 91058 Erlangen

A local approximation of current-density-functional theory [1] (LCDA) permits to derive a universal relation between current and density distributions in inhomogeneous systems [2]. We apply this relation to a homogeneous, non-interacting electron gas of a finite spatial extension. The magnetization of such a system is commonly calculated as a derivative of the free energy with respect to the magnetic field strength. Physically, however, it arises due to the diamagnetic persistent current at the edges of a system and one should be able to find it directly from the current density. We verify that LCDA indeed leads to a correct universal magnetization, despite the current density distribution is affected by the inaccuracy of the LCDA. Finally the applicability of the current-density relation to an inhomogeneous system in an ultra-strong magnetic field is studied for a non-interacting electron gas in a parabolic potential.

[1] G. Vignale and M. Rasolt, Phys. Rev. B 37, 10685 (1988)
[2] G. Vignale and P. Skudlarski, Phys. Rev. B 46, 10232 (1992)