Magnetotransport in p-type Ge quantum well narrow wire arrays

Journal Article · Mon Apr 27 00:00:00 EDT 2015 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4919053· OSTI ID:22398963

Llandro, J.; Mansell, R.; Barnes, C. H. W. ^[1]; Holmes, S. N. ^[2]; Morrison, C.; Foronda, J.; Myronov, M.; Leadley, D. R. ^[3]

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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)

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.

• OSTI ID: 22398963
• Journal Information: Applied Physics Letters, Vol. 106, Issue 17; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

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