Spatial structure of Mn-Mn acceptor pairs in GaAs.


The local density of states of Mn-Mn pairs in GaAs is mapped with cross-sectional scanning tunneling microscopy and compared with theoretical calculations based on envelope-function and tight-binding models. These measurements and calculations show that the crosslike shape of the Mn-acceptor wave function in GaAs persists even at very short Mn-Mn spatial separations. The resilience of the Mn-acceptor wave function to high doping levels suggests that ferromagnetism in GaMnAs is strongly influenced by impurity-band formation. The envelope-function and tight-binding models predict similarly anisotropic overlaps of the Mn wave functions for Mn-Mn pairs. This anisotropy implies differing Curie temperatures for Mn delta-doped layers grown on differently oriented substrates.

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@article{Yakunin2005SpatialSO, title={Spatial structure of Mn-Mn acceptor pairs in GaAs.}, author={Andrei M. Yakunin and Andrei Yu Silov and Paul M. Koenraad and J T Tang and Michael E . Flatt{\'e} and Willem Van Roy and Jo De Boeck and J . H . Wolter}, journal={Physical review letters}, year={2005}, volume={95 25}, pages={256402} }