Two-band superconductivity of Sn$_{1-x}$In$_{x}$Te crystals with $T_{c}$ = 3.6–3.8 K

The Andreev reflection spectra of high-quality superconducting Sn$_{1-x}$In$_{x}$Te crystals with critical temperature $T_{c}$ = 3.6–3.8 K were examined. The two-band nature of the superconducting state of this compound was established. The energy gaps have s-symmetry and were measured to be 2$\Delta_{1}/kT_{c}$ = 3.5 $\pm$ 0.9 and 2$\Delta_{2}/kT_{c}$ = 7 $\pm$ 1. Neither of the contacts with a resistance of 1.5–23 $\Omega$ revealed a peak at zero voltage typical of the topological superconducting state.