Electrically detected crystal orientation dependent spin-Rabi beat oscillation of c-Si(111)/SiO2interface states

Abstract

Electrically detected spin-Rabi beat oscillation of pairs of paramagnetic near interface states at the phosphorous doped (${10}^{16}$ cm${}^{\ensuremath{-}3}$) Si(111)/SiO${}_{2}$ interface is reported. Due to the $g$-factor anisotropy of the P${}_{b}$ center (a silicon surface dangling bond), one can tune intrapair Larmor frequency differences (Larmor separations) by orientation of the crystal with regard to an external magnetic field. Since Larmor separation governs the number of beating spin pairs, crystal orientation can control the beat current. This is used to identify spin states that are paired by mutual electronic transitions. The experiments confirm the presence of the previously reported ${}^{31}$P-P${}_{b}$ transition and provide direct experimental evidence of the previously hypothesized P${}_{b}$-${E}^{\ensuremath{'}}$ center (a near interface SiO${}_{2}$ bulk state) transition.