Electronic structure and magnetic properties of Mn and Fe impurities near GaAs (110) surface

Abstract

Combining density-functional theory calculations and microscopic tight-binding models, we investigate theoretically the electronic and magnetic properties of individual substitutional transition-metal impurities (Mn and Fe) positioned in the vicinity of the (110) surface of GaAs. For the case of the $[\mathrm{M}{\mathrm{n}}^{2+}{]}^0$ plus acceptor-hole (h) complex, the results of a tight-binding model including explicitly the impurity $d$-electrons are in good agreement with approaches that treat the spin of the impurity as an effective classical vector. For the case of Fe, where both the neutral isoelectronic $[\mathrm{F}{\mathrm{e}}^{3+}{]}^0$ and the ionized $[\mathrm{F}{\mathrm{e}}^{2+}{]}^{-}$ states are relevant to address scanning tunneling microscopy (STM) experiments, the inclusion of $d$-orbitals is essential. We find that the in-gap electronic structure of Fe impurities is significantly modified by surface effects. For the neutral acceptor state $[{\mathrm{Fe}}^{2+},h{]}^0$, the magnetic-anisotropy dependence on the impurity sublayer resembles the case of $[{\mathrm{Mn}}^{2+},h{]}^0$. In contrast, for $[{\mathrm{Fe}}^{3+}{]}^0$ electronic configuration the magnetic anisotropy behaves differently and it is considerably smaller. For this state we predict that it is possible to manipulate the Fe moment, e.g. by an external magnetic field, with detectable consequences in the local density of states probed by STM.

16 pages, 19 figures, Journal

References in corpus (7)

• Magnetic interactions in transition metal doped ZnO : An abinitio study
• Atom-by-Atom Substitution of Mn in GaAs and Visualization of their Hole-Mediated Interactions
• Spatial structure of an individual Mn acceptor in GaAs
• Multiband tight-binding model of local magnetism in GaMnAs
• STM images of sub-surface Mn atoms in GaAs: evidence of hybridization of surface and impurity states
• Spin-orientation-dependent spatial structure of a magnetic acceptor state in a zincblende semiconductor
• Mapping the wavefunction of transition metal acceptor states in the GaAs surface

Cited by in corpus (8)

• High-temperature intrinsic ferromagnetism in heavily Fe-doped GaAs layers
• Interplay between Mn-acceptor state and Dirac surface states in Mn-doped Bi${}_2$Se${}_3$ topological insulator
• Trend of the magnetic anisotropy for individual Mn dopants near the (110) GaAs surface
• Observation of the symmetry of core states of a single Fe impurity in GaAs
• Spin dynamics of Mn impurities and their bound acceptors in GaAs
• Fine structure of neutral acceptor states of isolated impurity in zinc-blende semiconductors
• Surface magnetism of gallium arsenide nanofilms
• Electric manipulation of the Mn-acceptor binding energy and the Mn-Mn exchange interaction on the GaAs (110) surface by nearby As vacancies