Critical temperatures for the observation of valley-splitting in Si-MOSFETS

At low temperatures the valley-splitting of Silicon MOS surface quantum states is enhanced by the difference of the Coulomb self-energies associate with the valley-split energy levels. The “critical temperature” T^C defines the upper limit of the temperature range O ≤ T < T^C within which the enhanced valley-splitting exceeds the line-width Γ so that it can be observed experimentally. The variation of T^C with the magnitude of the unenhanced “bare” valley-splitting ΔE^O is calculated for various magnetic fields and line-widths.