Probing zero-field splitting at spin-1 centers through dc magnetoresistance

Solid-state spins are promising candidates for quantum sensing and quantum information components due to remarkable spin coherence times. Electrical readout of single spins typically relies on Boltzmann distributed spin polarizations, which necessitate operation at low temperatures and/or high magnetic fields to improve the quality of the single-shot protocol [1]. Alternatively, coupling the coherent evolution with spin correlated transport via spin-polarized contact (or spin-polarized STM) is predicted to generate steady-state indicators of the coherent evolution in the low field (~mT) magnetoresistance without ac fields, even at room temperature [2]. These methods are not limited to spin-half states but can be applied to higher spin manifolds as well. We extend this method to the spin-1 neutral divacancy in 4H-SiC, where measurements of zero-field splittings on the order of GHz are resolvable using applied fields in the range of 50 mT as long as the carrier occupation time at the divacancy exceeds 1 ns. We acknowledge support for this work from DOE BES under Award Number DE-SC0016379.
[1] A. Morello, et al. Nature 467, 687(2010)
[2] S. R. McMillan, et al. Phys. Rev. Lett. in press (arXiv:1907.05509)