Chemical shift and exchange interaction energy of the $1s$ states of magnesium donors in silicon. The possibility of stimulated emission

The results of experiments aimed at the observation of split $1s$ states in Mg-doped Si are reported. From the results, it is possible to determine the chemical shift and exchange interaction energy of a neutral Mg donor in Si. The position of the $1s(E)$, $1s(T_2)$, and $2s(A_1)$ parastates determines the possibility for attaining population inversion and the specific mechanism of stimulated Raman scattering. The energy of the $1s(T_2)$ parastate is determined from the position of the Fano resonances in the photoconductivity spectrum of Si:Mg at $T$ = 4 K, and the energies of the $1s(T_2)$ and $1s(E)$ orthostates from the transmittance spectra at elevated temperatures. On the basis of the experimental data, the relaxation rates are estimated, and the possible mechanisms of stimulated emission are analyzed.