AVS 51st International Symposium
    Magnetic Interfaces and Nanostructures Wednesday Sessions
       Session MI-WeA

Paper MI-WeA2
Electronic Resonances of Isolated Mn and Interacting Mn-Mn Complexes on GaAs (110) Surfaces@footnote 1@

Wednesday, November 17, 2004, 2:20 pm, Room 304A

Session: Exchange Coupling, Surfaces, and Interfaces
Presenter: A. Richardella, University of Illinois at Urbana-Champaign
Authors: A. Richardella, University of Illinois at Urbana-Champaign
D. Kitchen, University of Illinois at Urbana-Champaign
A. Yazdani, University of Illinois at Urbana-Champaign
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Using low temperature scanning tunneling microscopy (STM) Mn on GaAs (110) surfaces has been studied. We present results for isolated Mn adatoms evaporated at low temperature on in situ cleaved n-type and p-type GaAs substrates. Localized modifications of the density of states of the substrates due to Mn are shown. Isolated Mn adatoms can exhibit two equivalent stable bonding states which STM atomic manipulation can induce transitions between. Additionally, certain tunneling parameters lead to increased mobility of Mn on the surface. It is shown isolated Mn's display a strong preference to pair along certain lattice directions. This pairing presents a unique opportunity for studying the interaction of magnetic impurities mediated through the underlying semiconductor states. Resonances due to these Mn-Mn interactions are presented using local density of states (LDOS) spectra and energy resolved spatial maps. In particular it is shown that similarly spaced Mn-Mn pairs can exhibit a number of distinct localized electronic resonances. Studies are ongoing into whether these varied localized states result from the relative spin orientations of the impurities with respect to each other and the surface. @FootnoteText@ @footnote 1@ This work was supported by ARO MURI DAAD19-01-1-0541.