2003/03/20 by L. Craco, Craco, L., M. S. Laad +4
Physics and Astronomy · #FOS: Physical sciences #Magnetic properties of thin films #Materials Science (cond-mat.mtrl-sci) #Physics of Superconductivity and Magnetism #Quantum and electron transport phenomena #Strongly Correlated Electrons (cond-mat.str-el) #cond-mat.mtrl-sci #cond-mat.str-el
paper · pdf · doi:10.48550/arxiv.cond-mat/0303427
4 pages, 3 figures, submitted to PRL
arxiv created 2003/03/20 · openalex publication_date 2003/03/20 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
There are two competing views of itinerant ferromagnetism, the first viewing ferromagnetism as resulting from the indirect coupling between local moments via the itinerant carrier dynamics, the so-called RKKY mechanism, while in the alternative picture, ferromagnetism results from the spin polarization of itinerant carriers by the strong atomic Hund interaction - the so-called double exchange (DE) scenario. Which view describes the ferromagnetism in diluted magnetic semiconductors, materials with promise for spintronic applications, is still unclear. Here, we describe the detailed physical response of the prototype material Ga1-xMnxAs using a combination of first-principles bandstructure with methods based on dynamical mean field theory to incorporate strong, dynamical correlations \it and intrinsic as well as extrinsic disorder in one single theoretical picture. We show how ferromagnetism is driven by DE, in agreement with very recent observations, along with a good quantitative description of the details of the electronic structure, as probed by scanning tunnelling microscopy (STM) and optical conductivity. Our results show how ferromagnetism can be driven by DE even in diluted magnetic semiconductors with small carrier concentration.