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HL: Halbleiterphysik

HL 3: III-V semiconductors I

HL 3.9: Vortrag

Montag, 27. März 2006, 12:15–12:30, POT 51

Scanning Tunneling Spectroscopy on single Mn-acceptors in InAs — •Felix Marczinowski¹, Jens Wiebe¹, Focko Meier¹, Katsushi Hashimoto¹, Markus Morgenstern², Roland Wiesendanger¹, Jiang-Ming Tang³, and Michael E. Flatté³ — ¹Institut für Angewandte Physik, Universität Hamburg, Jungiusstr. 11, 20355 Hamburg — ²2. Physikalisches Institut, RWTH-Aachen, Templergraben 55, 52056 Aachen — ³OSTC and Department of Physics and Astronomy, University of Iowa, Iowa City, Iowa 52242, USA

Ferromagnetic semiconductors like InMnAs receive a great amount of interest as the pivotal material for future spintronic devices. Recent experiments using STM suggest that the anisotropic shape of the acceptor wave function might affect the interaction of the magnetic dopants. [1,2] We performed scanning tunneling spectroscopy on Mn-doped InAs at low temperatures. In STM images, we find an anisotropic, cross-like shape of the Mn, which fits nicely to the Mn-acceptor wave function as calculated with the tight binding method. In contrast to the GaAs-case[1], Mn appears as a cross-like protrusion in the occupied density-of-states (DOS), and as a cross-like depression in the unoccupied DOS. These differences are probably explained by the different band-bending properties of InAs and GaAs. Additionally, we found several discrete states in dI/dU-curves which also reflect the symmetry of the Mn-acceptor wave function. The similarity of our findings to the GaAs-case[1] suggest that the cross-like shape is universal for Mn-acceptors in III-V-semiconductors.

[1] Yakunin et al., PRL 92, 216806 (2004)

[2] Arseev et al., JETP Lett. 77, 172 (2003)