Disentangling orbital and confinement contributions to $g$-factor in Ge/SiGe hole quantum dots

• URL: http://arxiv.org/abs/2602.09913v1
• Date: Tue, 10 Feb 2026 15:44:12 GMT
• Title: Disentangling orbital and confinement contributions to $g$-factor in Ge/SiGe hole quantum dots
• Authors: L. Sommer, I. Seidler, F. J. Schupp, S. Paredes, N. W. Hendrickx, L. Massai, S. W. Bedell, G. Salis, M. Mergenthaler, P. Harvey-Collard, A. Fuhrer, T. Ihn,
• Abstract summary: We investigate the out-of-plane $g$-factor in Ge quantum dots using excitation (single-particle) and addition (many-body) spectra.<n>We find gate-tunability of $g$-factors at the level of 15%, highlighting its relevance for all-electric qubit manipulation.
• Score: 0.0
• License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
• Abstract: Spin qubits are typically operated in the lowest orbital of a quantum dot to minimize interference from nearby states. In valence-band hole systems, strong spin-orbit coupling links spin and orbital degrees of freedom, strongly influencing the hole $g$-factor, a key parameter for qubit control. We investigate the out-of-plane $g$-factor in Ge quantum dots using excitation (single-particle) and addition (many-body) spectra. Excitation spectra allow us to distinguish the pure Zeeman $g$-factor from orbital contributions to the magnetic field splitting of states despite the strong spin-orbit coupling. This distinction clarifies discrepancies between $g$-factors extracted with the two methods, for different orbital states and different hole numbers. Furthermore, we find gate-tunability of $g$-factors at the level of 15%, highlighting its relevance for all-electric qubit manipulation.

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