Observation of the superconducting proximity effect in the surface state of SmB6 thin films

Abstract

The proximity effect at the interface between a topological insulator (TI) and a superconductor is predicted to give rise to chiral topological superconductivity and Majorana fermion excitations. In most TIs studied to date, however, the conducting bulk states have overwhelmed the transport properties and precluded the investigation of the interplay of the topological surface state and Cooper pairs. Here, we demonstrate the superconducting proximity effect in the surface state of SmB6 thin films which display bulk insulation at low temperatures. The Fermi velocity in the surface state deduced from the proximity effect is found to be as large as 10^5 m/s, in good agreement with the value obtained from a separate transport measurement. We show that high transparency between the TI and a superconductor is crucial for the proximity effect. The finding here opens the door to investigation of exotic quantum phenomena using all-thin-film multilayers with high-transparency interfaces.

References in corpus (18)

• Non-Abelian Anyons and Topological Quantum Computation
• Superconducting proximity effect and Majorana fermions at the surface of a topological insulator
• Topological Field Theory of Time-Reversal Invariant Insulators
• Correlated Topological Insulators with Mixed Valence
• Topological Kondo Insulators
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• Composition-spread Growth and the Robust Topological Surface State of Kondo insulator SmB6 Thin Films
• Surface state reconstruction in ion-damaged SmB_6
• Robust Surface States indicated by Magnetotransport in SmB6 Thin Films
• Proximity effects at the interface of a superconductor and a topological insulator in NbN - Bi_2Se_3 thin film bilayers

Cited by in corpus (9)

• Magnetoelectrics in Disordered Topological Insulator Josephson Junctions
• Observation of perfect Andreev reflection due to Klein paradox in a topological superconducting state
• Definitive Surface Magnetotransport Study of SmB${}_6$
• Size Constraints on Majorana Beamsplitter Interferometer: Majorana Coupling and Surface-Bulk Scattering
• Unconventional Josephson junctions with topological Kondo insulator weak links
• Microwave Meissner Screening of Proximity coupled Topological Insulator / Superconductor Bilayers
• Surface excitations relaxation in the Kondo insulator Sm${}_{1-x}$Gd${}_x$B${}_6$
• Observation of the superconducting proximity effect from surface states in SmB${}_6$/YB${}_6$ thin film heterostructures via terahertz spectroscopy
• Tunable zero-energy Dirac and Luttinger nodes in a two-dimensional topological superconductor