Spatially resolved electronic structure of an isovalent nitrogen center in GaAs

Abstract

Small numbers of nitrogen dopants dramatically modify the electronic properties of GaAs, generating very large shifts in the conduction-band energies with nonlinear concentration dependence, and impurity-associated spatially-localized resonant states within the conduction band. Cross-sectional scanning tunneling microscopy provides the local electronic structure of single nitrogen dopants at the (110) GaAs surface, yielding highly anisotropic spatial shapes when the empty states are imaged. Measurements of the resonant states relative to the GaAs surface states and their spatial extent allow an unambiguous assignment of specific features to nitrogen atoms at different depths below the cleaved (110) surface. Multiband tight binding calculations around the resonance energy of nitrogen in the conduction band match the imaged features. The spatial anisotropy is attributed to the tetrahedral symmetry of the bulk lattice. Additionally, the voltage dependence of the electronic contrast for two features in the filled state imaging suggest these features could be related to a locally modified surface state.

References in corpus (5)

• 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
• Mapping the wavefunction of transition metal acceptor states in the GaAs surface
• Interplay between quantum confinement and dielectric mismatch for ultra-shallow dopants

Cited by in corpus (4)

• Atomic-level Characterisation of Quantum Computer Arrays by Machine Learning
• N-nH complexes in GaAs studied at the atomic scale by cross-sectional scanning tunneling microscopy
• Probing the local electronic structure of isovalent Bi atoms in InP
• Influence of sample momentum space features on scanning tunnelling microscope measurements