Light effective hole mass in undoped Ge/SiGe quantum wells

Journal article (2019)

Authors

M. Lodari QCD/Scappucci Lab - QuTech Advanced Research Centre , Kavli institute of nanoscience Delft, QuTech Advanced Research Centre
A. Tosato QuTech Advanced Research Centre, QCD/Scappucci Lab - QuTech Advanced Research Centre , Kavli institute of nanoscience Delft
D. Sabbagh Kavli institute of nanoscience Delft, QCD/Scappucci Lab - QuTech Advanced Research Centre , QuTech Advanced Research Centre
Markus Schubert Innovations for High Performance Microelectronics
Giovanni Capellini University of Roma Tre, Innovations for High Performance Microelectronics
A. Sammak Business Development , TNO
M. Veldhorst QCD/Veldhorst Lab - QuTech Advanced Research Centre
G. Scappucci QuTech Advanced Research Centre, Kavli institute of nanoscience Delft, QCD/Scappucci Lab - QuTech Advanced Research Centre
Research Group
QCD/Scappucci Lab (QuTech Advanced Research Centre) (TU Delft)
Copyright: © 2019 M. Lodari, A. Tosato, D. Sabbagh, M. A. Schubert, G. Capellini, A. Sammak, M. Veldhorst, G. Scappucci
DOI
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https://doi.org/10.1103/PhysRevB.100.041304
More Info
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Published Date

2019

Language

English

Faculty

QuTech Advanced Research Centre

Department

Quantum Computing Division

Research Group

QCD/Scappucci Lab

Abstract

We report density-dependent effective hole mass measurements in undoped germanium quantum wells. We are able to span a large range of densities (2.0-11×1011cm-2) in top-gated field effect transistors by positioning the strained buried Ge channel at different depths of 12 and 44 nm from the surface. From the thermal damping of the amplitude of Shubnikov-de Haas oscillations, we measure a light mass of 0.061me at a density of 2.2×1011cm-2. We confirm the theoretically predicted dependence of increasing mass with density and by extrapolation we find an effective mass of ∼0.05me at zero density, the lightest effective mass for a planar platform that demonstrated spin qubits in quantum dots.