Point-contact measurements of the energy gap of lead-chalcogenide-based   superconducting superlattices
  The energy gap of superconducting $PbTe-PbS$ semiconductor superlattices has been analyzed with the help of point contacts for the first time below the critical temperature, $T_{c}=3.9~K$, and in the fluctuation region $T>T_{c}$. The size of the gap and its dependence on the temperature and field are determined by the position of the point contact inside the superlattice. \pacs{73.40.Jn, 74.25.Kc, 74.45.+c, 74.50.+r., 73.40.-c, 74.78.-w, 74.78.Fk, 74.20.Mn, 74.40.+k.-n, 74.45.+c, 74.62.Dn, 74.70.Ad 
I.K. Yanson, N.L. Bobrov, L.F. Rybal'chenko, V.V. Fisun, O.A. Mironov,   S.V. Chistyakov, A.Yu. Sipatov, and A.I. Fedorenko
cond-mat.supr-con