Superconductivity in Sn${}_{1-x}$In${}_x$Te thin films grown by molecular beam epitaxy

Abstract

The superconductor Sn${}_{1-x}$In${}_x$Te is derived from the topological crystalline insulator SnTe and is a candidate topological superconductor. So far, high-quality thin films of this material have not been available, even though such samples would be useful for addressing the nature of its superconductivity. Here we report the successful molecular beam epitaxy growth of superconducting Sn${}_{1-x}$In${}_x$Te films by using Bi${}_2$Te${}_3$ as a buffer layer. The data obtained from tunnel junctions made on such films show the appearance of two superconducting gaps, which points to the coexistence of bulk and surface superconductivity. Given the spin-momentum locking of the surface states, the surface superconductivity is expected to be topological with an effective $p$-wave character. Since the topological surface states of SnTe consist of four Dirac cones, this platform offers an interesting playground for studying topological surface superconductivity with additional degrees of freedom.

6+3 pages, 6+2 figures

References in corpus (3)

• Superconducting proximity effect and Majorana fermions at the surface of a topological insulator
• Odd-Parity Pairing and Topological Superconductivity in a Strongly Spin-Orbit Coupled Semiconductor
• Enhanced superconducting pairing interaction in indium-doped tin telluride

Cited by in corpus (1)

• Molecular beam epitaxy of superconducting Sn${}_{1-x}$In${}_x$Te thin films