Dissipative tunneling in two-state systems at the Si/SiO2 interface.

Abstract

We have observed two-state systems (TSSs) in electrically stressed metal-oxide-silicon field-effect transistors, by studying random telegraph signals at low temperatures. The TSSs are related to defects close to the Si/${\mathrm{SiO}}_{2}$ interface. The asymmetry energy \ensuremath{\varepsilon} is linear in gate voltage, permitting for the first time measurement of the dissipative tunneling rate as a function of \ensuremath{\varepsilon} independently of magnetic field. The electron coupling strength \ensuremath{\alpha} lies in the range ${10}^{\mathrm{\ensuremath{-}}3}$ to ${10}^{\mathrm{\ensuremath{-}}2}$, allowing comparison with the standard theory in the previously unexplored regime of weak coupling.