Onset of a Two-Dimensional Superconducting Phase in a Topological-Insulator–Normal-Metal Bi1−xSbx/Pt Junction Fabricated

Abstract

Inducing superconductivity in a topological insulator can lead to novel quantum effects. However, experimental approaches to turn a topological insulator into a superconductor are limited. Here, we report on superconductivity in topological insulator Bi_{0.91}Sb_{0.09} induced via focused ion-beam deposition of a Pt thin film. The superconducting phase exhibits a Berezinski-Kosterlitz-Thouless transition, demonstrative of its two-dimensional character. From the in-plane upper critical field measurements, we estimate the superconducting thickness to be ∼17 nm for a 5.5-μm-thick sample. Our results provide evidence that the interface superconductivity could originate from the surface states of Bi_{0.91}Sb_{0.09}.

Classifying Induced Superconductivity in Atomically Thin Dirac-Cone Materials

“…Many interesting physical effects are expected if non-superconducting part of S/N/S junction will be made of single-layer graphene (SLG) [7], multiple-layer graphene (MLG) [8], graphene-like materials [9], and many other new 2D-and nano-DCMs which are under on-going discover/invent/exploration stage now . One certainly interesting class of S/N/S junctions is when non-superconducting part of the device made of topological insulators (TI) [40][41][42][43][44][45][46][47]. Temperature dependent self-field critical currents, Ic(sf,T) in this class of junctions were first reported by Veldhorst et al in Nb/Bi2Te3/Nb [18], and later by Kurter et al in Nb/Bi2Se3/Nb [19], by Charpentier et al in Al/Bi2Te3/Al [42], and by other research groups in different systems (extended reference list for studied S/TI/S junctions can be found in Refs.…”

Classifying superconductivity in an infinite-layer nickelate Nd0.8Sr0.2NiO2

“…where ( ) = ; polar configuration (15) ( ) = √1 − 2 ; axial configuration (16) More details about the Jc(sf,T) analysis for p-wave symmetry can be found elsewhere [26,27]. This approach is recently applied for wide range of thin film unconventional superconductors [23,24,[26][27][28][29][30][31][32].…”

Classifying Superconductivity in an Infinite-Layer Nickelate Nd_0.8Sr_0.2NiO₂

“…More details about the Jc(sf,T) analysis for p-wave symmetry can be found elsewhere [26,27]. This approach is recently applied for wide range of thin film unconventional superconductors [23,24,[26][27][28][29][30][31][32].…”