Regensburg 2007 – wissenschaftliches Programm

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MA: Fachverband Magnetismus

MA 4: Electron Theory of Magnetism

MA 4.4: Vortrag

Montag, 26. März 2007, 11:00–11:15, H23

Residual resistance calculations of Ga_1−xMn_xAs using the Kubo-Greenwood formalism — •Stephan Lowitzer¹, Stanislav Chadov¹, Voicu Popescu^2,1, and Hubert Ebert¹ — ¹Department Chemie/Physikalische Chemie, LMU München, Butenandstraße 5-13, 81377 München — ²Max-Planck-Institut für Metallforschung, Heisenbergstr. 3, 70569 Stuttgart

The residual resistance (at T = 0K) of the diluted magnetic semiconductor system (DMS) Ga_1−xMn_xAs has been calculated. For these calculations the Kubo-Greenwood formalism has been employed. The electronic structure calculations is based on the Korringa-Kohn-Rostoker (KKR) band structure method in connection with the coherent potential approximation (CPA) alloy theory. The results show in accordance with other authors a fast decrease of the resistivity with increasing Mn-concentration. This behavior is due to an increase of the density of states at the Fermi edge. Additional calculations show, that the occupation of interstitial positions or the occupation of antisites lead to a clear increase of the resistivity due to disorder. These calculations are in good agreement with experimental data for untreated and tempered samples. Further calculations indicate a small influence of the spin-orbit-coupling on the isotropic residual resistance.