Spectroscopy of Spin-Orbit Quantum Bits in Indium Antimonide Nanowires
A double quantum dot in the few-electron regime is achieved using local gating in an InSb nanowire. The spectrum of two-electron eigenstates is investigated using electric dipole spin resonance. Singlet-triplet level repulsion caused by spin-orbit interaction is observed. The size and the anisotropy of singlet-triplet repulsion are used to determine the magnitude and the orientation of the spin-orbit effective field in an InSb nanowire double dot. The obtained results are confirmed using spin blockade leakage current anisotropy and transport spectroscopy of individual quantum dots.
Additional Information© 2012 American Physical Society. Received 9 January 2012; published 19 April 2012. We would like to thank J. Danon, Y. Nazarov, M. Rudner, D. Loss, F. Hassler, and J. van Tilburg for discussions and help. We acknowledge help with the measurement software from R. Heeres and P. de Groot. This work has been supported by ERC, NWO/FOM Netherlands Organization for Scientific Research, and through the DARPA program QUEST.
Published - PhysRevLett.108.166801.pdf
Submitted - 1201.3707v2.pdf