An experimental study on the nature of spin-dependent excess charge carrier transitions at the interface between (111) oriented phosphorous doped ([P] ~ 10^15 cm^3) crystalline silicon and silicon dioxide at high magnetic field (B_0 ~ 8.5 T) is presented. Electrically detected magnetic resonance (EDMR) spectra of the hyperfine split 31P donor electron transitions and paramagnetic interface defects were conducted at temperatures in the range 3 K < T < 12 K. The results at these previously unattained (for EDMR) magnetic field strengths reveal the dominance of spin-dependent processes that differ from the previously well investigated recombination between the 31P donor and the P_b state, which dominates at low magnetic fields. While magnetic resonant current responses due to 31P and P_b states are still present, they do not correlate and only the P_b contribution can be associated with an interface process due to spin-dependent tunneling between energetically and physically adjacent P_b states. This work provides an experimental demonstration of spin-dependent tunneling between physically adjacent and identical electronic states as proposed by Kane for readout of donor qubits.
@article{arxiv.0802.0230,
title = {Spin-dependent processes at the crystalline Si-SiO_2 interface at high magnetic fields},
author = {D. R. McCamey and G. W. Morley and H. A. Seipel and L. C. Brunel and J. van Tol and C. Boehme},
journal= {arXiv preprint arXiv:0802.0230},
year = {2008}
}