Magnetic transport measurements of spin–orbit and hyperfine interactions in a Ge hut wire double quantum dot

Ge quantum dots are emerging as an attractive platform to realize high-fidelity qubits because of their strong spin–orbit interaction (SOI) and weak hyperfine interaction (HFI). Here, we measure and analyze the transport spectra on a highly tunable double quantum dot (DQD) defined in Ge hut wires with an external out-of-plane magnetic field. At a high magnetic field, the SOI induced spin-flip tunneling lifts the Pauli spin blockade and maps out the energy spectrum of the DQD. At a low magnetic field, the HFI mixes the (1, 1) states and leads to an enhanced leakage current, which is affected by the inter-dot tunnel coupling.