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

Abstract

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 high magnetic field, the SOI induced spin-flip tunneling lifts the Pauli spin blockade (PSB) and maps out the energy spectrum of DQD. At 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.