Quantum-chemical study of structure and vibrational spectra of Si/SiO$_2$ superlattices

Structure, phonon states and vibrational spectra of binary Si/SiO$_2$ superlattices (SL) formed by junction of crystalline silicon and $\beta$-cristobalite are investigated with the use of ab-initio quantum-mechanical computational methods. Several stable SL structures with ultra-narrow interfaces consisted of only one monolayer of Si$^{2+}$ atoms are found. For these SLs, we have simulated the infrared and Raman spectra in which some characteristic spectral features are detected.