Electron and hole gas in modulation-doped GaAs/Al{sub 1-x}Ga{sub x}As radial heterojunctions

Journal Article · Tue Nov 15 00:00:00 EST 2011 · Physical Review. B, Condensed Matter and Materials Physics

DOI:https://doi.org/10.1103/PHYSREVB.84.205323· OSTI ID:21596925

Bertoni, Andrea; Royo, Miquel; Mahawish, Farah; Goldoni, Guido ^[1]

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1. CNR-NANO S3, Istituto Nanoscienze, Via Campi 213/a, 41125 Modena (Italy)

We perform self-consistent Schroedinger-Poisson calculations with exchange and correlation corrections to determine the electron and hole gas in a radial heterojunction formed in a GaAs/AlGaAs core-multi-shell nanowire, which is either n- or p-doped. We show that the electron and hole gases can be tuned to different localizations and symmetries inside the core as a function of the doping density/gate potential. Contrary to planar heterojunctions, conduction electrons do not form a uniform 2D electron gas (2DEG) localized at the GaAs/AlGaAs interface, but rather show a transition between an isotropic, cylindrical distribution deep in the GaAs core (low doping) and a set of six tunnel-coupled quasi-1D channels at the edges of the interface (high doping). Holes, on the other hand, are much more localized at the GaAs/AlGaAs interface. At low doping, they present an additional localization pattern with six separated 2DEGs strips. The field generated by a back-gate may easily deform the electron or hole gas, breaking the sixfold symmetry. Single 2DEGs at one interface or multiple quasi-1D channels are shown to form as a function of voltage intensity, polarity, and carrier type.

• OSTI ID: 21596925
• Journal Information: Physical Review. B, Condensed Matter and Materials Physics, Vol. 84, Issue 20; Other Information: DOI: 10.1103/PhysRevB.84.205323; (c) 2011 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 1098-0121
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ALUMINIUM ARSENIDES
CORRELATIONS
CYLINDRICAL CONFIGURATION
DENSITY
DISTRIBUTION
DOPED MATERIALS
ELECTRIC POTENTIAL
ELECTRON GAS
ELECTRONS
GALLIUM ARSENIDES
HETEROJUNCTIONS
HOLES
INTERFACES
MODULATION
QUANTUM WIRES
SYMMETRY
ALUMINIUM COMPOUNDS
ARSENIC COMPOUNDS
ARSENIDES
CONFIGURATION
ELEMENTARY PARTICLES
FERMIONS
GALLIUM COMPOUNDS
LEPTONS
MATERIALS
NANOSTRUCTURES
PHYSICAL PROPERTIES
PNICTIDES
SEMICONDUCTOR JUNCTIONS