Effective g factor of low-density two-dimensional holes in a Ge quantum well

Abstract

We report measurements of the effective $g$ factor of low-density two-dimensional holes in a Ge quantum well. Using the temperature dependence of the Shubnikov-de Haas oscillations, we extract the effective $g$ factor in a magnetic field perpendicular to the sample surface. Very large values of the effective $g$ factor, ranging from $\sim 13$ to $\sim 28$, are observed in the density range of $1.4\times 10^{10}$ cm${}^{-2}$ to $1.4\times 10^{11}$ cm${}^{-2}$. When the magnetic field is oriented parallel to the sample surface, the effective $g$ factor is obtained from a protrusion in the magneto-resistance data that signifies full spin polarization. In the latter orientation, a small effective $g$ factor, $\sim 1.3-1.4$, is measured in the density range of $1.5\times 10^{10}$ cm${}^{-2}$ to $2\times 10^{10}$ cm${}^{-2}$. This very strong anisotropy is consistent with theoretical predictions and previous measurements in other 2D hole systems, such as InGaAs and GaSb.

References in corpus (2)

• Cubic Rashba spin-orbit interaction of two-dimensional hole gas in strained-Ge/SiGe quantum well
• Density-controlled quantum Hall ferromagnetic transition in a two-dimensional hole system

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• Majorana zero modes in gate-defined germanium hole nanowires
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• Electrical operation of hole spin qubits in planar MOS silicon quantum dots
• Anisotropic $g$-tensors in hole quantum dots: The role of the transverse confinement direction
• Effective out-of-plane g-factor in strained-Ge/SiGe quantum dots
• Probing details of spin--orbit coupling through Pauli spin blockade