Spectroscopy of spin-orbit quantum bits in indium antimonide nanowires

Phys Rev Lett. 2012 Apr 20;108(16):166801. doi: 10.1103/PhysRevLett.108.166801. Epub 2012 Apr 19.


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.