Gate-Tunable Spin-Orbit Coupling in a Germanium Hole Double Quantum Dot

TL;DR

This paper demonstrates a gate-tunable spin-orbit interaction in a Germanium double quantum dot, enabling potential for fast, electric spin control and improved qubit coherence in quantum computing applications.

Contribution

The study experimentally shows a controllable spin-orbit interaction in Ge hole quantum dots, with tunable spin-orbit length, advancing qubit technology.

Findings

Measured spin-orbit length tunable from 2.0 to 48.9 nm.

Achieved control of spin-orbit interaction via interdot tunnel coupling.

Potential for high-fidelity qubit implementation in Ge systems.

Abstract

Hole spins confined in semiconductor quantum dot systems have gained considerable interest for their strong spin-orbit interactions (SOIs) and relatively weak hyperfine interactions. Here we experimentally demonstrate a tunable SOI in a double quantum dot in a Germanium (Ge) hut wire (HW), which could help enable fast all-electric spin manipulations while suppressing unwanted decoherence. Specifically, we measure the transport spectra in the Pauli spin blockade regime in the double quantum dot device.By adjusting the interdot tunnel coupling, we obtain an electric field tuned spin-orbit length lso = 2.0 - 48.9 nm. This tunability of the SOI could pave the way toward the realization of high-fidelity qubits in Ge HW systems.