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Title: Disorder effects on resonant hole tunneling transport in (Ga,Mn)As/GaAs heterostructures

Recent experiments on resonant tunneling structures comprising (Ga,Mn)As quantum wells [Ohya et al., Nature Physics 7, 342 (2011)] have evoked strong debates about the near absence of resonant tunneling features and ferromagnetic order observed in these structures. Here, we present a theoretical examination of a GaAs/(Ga,Mn)As double barrier structure, studying the self-consistent interplay between ferromagnetic order, structural defects, and the hole tunnel current. The hole band structure is described by a four band Kohn-Luttinger Hamiltonian and the transport characteristics are obtained within the non-equilibrium Green’s function approach taking into account space charge effects. We show that disorder has a strong influence on the current-voltage characteristics in efficiently reducing or even washing out negative differential conductance, as found in experiment. We find that for the Be lead doping levels used in experiment the resulting spin density polarization in the quantum well is too small to produce sizable exchange splittings.
Authors:
;  [1]
  1. Institute of Physics, Karl-Franzens University Graz, Universitätsplatz 5, A-8010 Graz (Austria)
Publication Date:
OSTI Identifier:
22261785
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 1566; Journal Issue: 1; Conference: ICPS 2012: 31. international conference on the physics of semiconductors, Zurich (Switzerland), 29 Jul - 3 Aug 2012; Other Information: (c) 2013 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
77 NANOSCIENCE AND NANOTECHNOLOGY; DENSITY; ELECTRIC POTENTIAL; GALLIUM ARSENIDES; HAMILTONIANS; POLARIZATION; QUANTUM WELLS; TUNNEL EFFECT