AVS 50th International Symposium
    Semiconductors Thursday Sessions
       Session SC+MI-ThA

Paper SC+MI-ThA3
Microscopic Valence Band Structure Near Mn and Local Magnetism in Ga@sub 1-x@Mn@sub x@As

Thursday, November 6, 2003, 2:40 pm, Room 321/322

Session: Ferromagnetic and Dilute Magnetic Semiconductors
Presenter: J. Tang, University of Iowa
Authors: J. Tang, University of Iowa
M.E. Flatté, University of Iowa
Correspondent: Click to Email
The microscopic spin-dependent disturbances to the valence band near Mn atoms in Ga@sub 1-x@Mn@sub x@As and the indirect Mn-Mn interaction are studied. The GaAs host is described by a multiband tight-binding Hamiltonian that incorporates spin-orbit interaction, and the Mn impurity is described by a local p-d hybridization and on-site potential. Local spin-polarized resonances within the valence band that significantly enhance the LDOS near the band edge. The quantitative enhancement we calculate is consistent with angle-resolved photoemission and interband magnetoabsorption measurements. We present the hybridization energy for two parallel Mn magnetic moments. The splitting of the acceptor level is highly anisotropic and exceeds 10 meV even if the Mn impurities are separated by as many as 20 Å. This suggests that scanning tunneling spectroscopy can probe the Mn spin orientation and measure the Mn-Mn interaction energy as a function of distance. This work was supported by the ARO MURI DAAD19-01-1-0541.