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Title: Magnetotransport in p-type Ge quantum well narrow wire arrays

We report magnetotransport measurements of a SiGe heterostructure containing a 20 nm p-Ge quantum well with a mobility of 800 000 cm{sup 2} V{sup −1} s{sup −1}. By dry etching arrays of wires with widths between 1.0 μm and 3.0 μm, we were able to measure the lateral depletion thickness, built-in potential, and the phase coherence length of the quantum well. Fourier analysis does not show any Rashba related spin-splitting despite clearly defined Shubnikov-de Haas oscillations being observed up to a filling factor of ν = 22. Exchange-enhanced spin-splitting is observed for filling factors below ν = 9. An analysis of boundary scattering effects indicates lateral depletion of the hole gas by 0.5 ± 0.1 μm from the etched germanium surface. The built-in potential is found to be 0.25 ± 0.04 V, presenting an energy barrier for lateral transport greater than the hole confinement energy. A large phase coherence length of 3.5 ± 0.5 μm is obtained in these wires at 1.7 K.
Authors:
; ; ;  [1] ;  [2] ; ; ; ;  [3]
  1. Department of Physics, Cavendish Laboratory, University of Cambridge, J. J. Thomson Avenue, Cambridge CB3 0HE (United Kingdom)
  2. Toshiba Research Europe Limited, Cambridge Research Laboratory, 208 Cambridge Science Park, Milton Road, Cambridge CB4 0GZ (United Kingdom)
  3. Department of Physics, University of Warwick, Coventry CV4 7AL (United Kingdom)
Publication Date:
OSTI Identifier:
22398963
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 106; Journal Issue: 17; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; 77 NANOSCIENCE AND NANOTECHNOLOGY; CARRIER MOBILITY; COHERENCE LENGTH; CONFINEMENT; DIFFUSION BARRIERS; ETCHING; FOURIER ANALYSIS; GERMANIUM; GERMANIUM SILICIDES; HOLES; OSCILLATIONS; POTENTIALS; QUANTUM WELLS; SCATTERING; SHUBNIKOV-DE HAAS EFFECT; SPIN; SURFACES