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

Abstract

We demonstrate that a lightly-strained germanium channel (${\epsilon }_{//}$ = -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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Cited by in corpus (22)

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• Hard superconducting gap in germanium
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• Hole spin manipulation in inhomogeneous and non-separable electric fields
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• Determination of spin-orbit interaction in semiconductor nanostructures via non-linear transport
• Electrical operation of hole spin qubits in planar MOS silicon quantum dots
• High quality CVD deposition of Ge layers for Ge/SiGe Quantum Well heterostructures
• Germanium-based hybrid semiconductor-superconductor topological quantum computing platforms: Disorder effects
• Modelling of planar germanium hole qubits in electric and magnetic fields
• Molecular beam epitaxy growth of superconducting tantalum germanide
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• A spinless spin qubit
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• Impact of surface treatments on the transport properties of germanium 2DHGs
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• Supercurrent and multiple Andreev reflections in Ge hut nanowire Josephson Junctions