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arXiv · 2112.11860

Lightly-strained germanium quantum wells with hole mobility exceeding one million

M. Lodari·O. Kong·M. Rendell·A. Tosato·A. Sammak·M. Veldhorst·A. R. Hamilton·G. Scappucci
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Abstract

We demonstrate that a lightly-strained germanium channel ($\varepsilon_{//}$ = -0.41%) in an undoped Ge/Si$_{0.1}$Ge$_{0.9}$ heterostructure field effect transistor supports a 2D hole gas with mobility in excess of 1$\times$10$^{6}$ cm$^{2}$/Vs and percolation density less than 5$\times$10$^{10}$ cm$^{-2}$. This low disorder 2D hole system shows tunable fractional quantum Hall effect at low density and low magnetic field. The low-disorder and small effective mass (0.068$m_e$) defines lightly-strained germanium as a basis to tune the strength of the spin-orbit coupling for fast and coherent quantum hardware.

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M. Lodari, O. Kong, M. Rendell, A. Tosato, A. Sammak, M. Veldhorst, A. R. Hamilton, G. Scappucci. 2021-12-22. Lightly-strained germanium quantum wells with hole mobility exceeding one million. https://doi.org/10.1063/5.0083161

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