STM Images of Subsurface Mn Atoms in GaAs: Evidence of Hybridization of Surface and Impurity States

CNRS-Laboratoire de Photonique et de Nanostructures, route de Nozay, F-91460, Marcoussis, France.
Physical Review Letters (Impact Factor: 7.73). 12/2008; 101(19):196801. DOI: 10.1103/PhysRevLett.101.196801
Source: arXiv

ABSTRACT We show that scanning tunneling microscopy (STM) images of subsurface Mn atoms in GaAs are formed by hybridization of the impurity state with intrinsic surface states. They cannot be interpreted in terms of bulk-impurity wave-function imaging. Atomic-resolution images obtained using a low-temperature apparatus are compared with advanced, parameter-free tight-binding simulations accounting for both the buckled (110) surface and vacuum electronic properties. Splitting of the acceptor state due to buckling is shown to play a prominent role.


Available from: M. O. Nestoklon, Jun 11, 2015
1 Follower
  • [Show abstract] [Hide abstract]
    ABSTRACT: The properties of neutral acceptor states in GaAs are re-examined in the frame of extended-basis &$s{{p}^{3}}{{d}^{5}}{{s}^{*}}$; tight-binding model. Spherical harmonics decomposition of microscopic local density of states (LDOS) allows for the direct analysis of the tight-binding results in terms of k · p approximation. Lifting of degeneracy by strain and electric field and their effect on LDOS are examined. The fine structure of magnetic impurity caused by exchange interaction of hole with impurity d-shell and its dependence on strain is studied. It is shown that exchange interaction makes the ground state more isotropic.
    Semiconductor Science and Technology 03/2015; 30(3). DOI:10.1088/0268-1242/30/3/035019 · 2.21 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The nature of the ground optical transition in an (In,Ga)As/GaP quantum dot is thoroughly investigated through a million atoms supercell tight-binding simulation. Precise quantum dot morphology is deduced from previously reported scanning-tunneling-microscopy images. The strain field is calculated with the valence force field method and has a strong influence on the confinement potentials, principally, for the conduction band states. Indeed, the wavefunction of the ground electron state is spatially confined in the GaP matrix, close to the dot apex, in a large tensile strain region, having mainly Xz character. Photoluminescence experiments under hydrostatic pressure strongly support the theoretical conclusions. (C) 2014 AIP Publishing LLC.
    Applied Physics Letters 01/2014; 104(1-1). DOI:10.1063/1.4861471 · 3.52 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Band structure calculations of complete InAs monolayer in AlGaAs/GaAs quantum wells are performed within the framework of the extended-basis sp3d5s* tight-binding model. We show that the optical properties can be tuned from the quantum well energy below the GaAs band-gap depending on the well thickness and the position of the probe. The results are supported by differential reflectivity measurements and represent a concept for optoelectronic devices with an operation wavelength widely tuneable around 850 nm employing GaAs process technology.
    Applied Physics Letters 07/2012; 101(1):012105. DOI:10.1063/1.4731783 · 3.52 Impact Factor