As a follow up to our finding that CuCl/Si superlattices exhibit metallicity at the interfaces and possibly superconductivity, we explore other semiconductor superlattices for the same properties and present here our results for ZnS/Si and GaP/Si superlattices. As found for the CuCl/Si superlattices, both the ZnS/Si and GaP/Si superlattices exhibit two-dimensional metallicity at their interfaces, as shown by their band structures, Fermi surfaces, and charge-density distributions. Furthermore, to gauge any possible superconductivity, the McMillan-Hopfield electron-phonon coupling constant, λ, is calculated using the rigid muffin-tin approximation. Electron-phonon coupling is observed mostly at the interfaces but it is not strong enough to cause superconductivity at a finite temperature as estimated using the McMillan formula for Tc. This contrasts greatly with the CuCl/Si superlattices, in which electron-phonon coupling is strong enough to indicate superconductivity.
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|Publication status||Published - Jan 5 2009|
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics