Konwersatorium im. Leopolda Infelda
Nowa Auli (425), ul. Hoża 69
2011-03-03 (15:30) 
prof. dr hab. Tomasz Dietl (Laboratory of Cryogenic and Spintronic Research, Institute of Physics, Polish Academy of Sciences; Institute of Theoretical Physics Faculty of Physics University of Warsaw)
Understanding the origin of ferromagnetism in semiconductors
To memory of Jan Gaj (1943-2011)
In course of the years, the origin of spontaneous magnetisation that has been observed in numerous semiconductors and oxides has arguably become one of the most controversial topics in the contemporary physics of condensed matter. After a general introduction to spintronics and magnetically doped semiconductors, I will argue [1] that surprising properties of these systems have two distinct roots (i) an intricate interplay between hole-mediated ferromagnetism and AndersonMott localisation and (ii) a highly non-random distribution of magnetic cations driven by a significant contribution of open d shells to the cohesive energy.
[1] see, T. Dietl, Nature Mat. 9, 965 (2010), and references therein.