We present measurements on gate-defined double quantum dots in Ge-Si core-shell nanowires, which we tune to a regime with visible shell filling in both dots. We observe a Pauli spin blockade and can assign the measured leakage current at low magnetic fields to spin-flip cotunneling, for which we measure a strong anisotropy related to an anisotropic g factor. At higher magnetic fields we see signatures for leakage current caused by spin-orbit coupling between (1,1) singlet and (2,0) triplet states. Taking into account these anisotropic spin-flipmechanisms,we can choose the magnetic field direction with the longest spin lifetime for improved spin-orbit qubits.
|Number of pages||5|
|Journal||Physical review B: Covering condensed matter and materials physics|
|Publication status||Published - 22 Jul 2016|
Brauns, M., Ridderbos, J., Ridderbos, J., Li, A., Bakkers, E. P. A. M., van der Wiel, W. G., & Zwanenburg, F. A. (2016). Anisotropic Pauli spin blockade in hole quantum dots. Physical review B: Covering condensed matter and materials physics, 94, 041411. https://doi.org/10.1103/PhysRevB.94.041411