2011/09/29 by Andrea Bertoni, Miquel Royo, Farah Mahawish +1 · 2 citations
Engineering · Physics and Astronomy · #Advancements in Semiconductor Devices and Circuit Design #Condensed matter physics #Doping #Electron #Fermi gas #Heterojunction #Materials science #Nanowire Synthesis and Applications #Physics #Planar #Quantum mechanics #Semiconductor Quantum Structures and Devices #cond-mat.mes-hall
paper · pdf · doi:10.1103/physrevb.84.205323
published as Phys. Rev. B 84, 205323 (2011) · 22 pages, revtex4 preprint format, submitted
arxiv created 2011/09/29 · openalex publication_date 2011/11/18 · arxiv updated 2016/04/29 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We perform self-consistent Schr"odinger-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.