Unexpected superconductivity at nanoscale junctions made on the topological crystalline insulator Pb${}_{0.6}$Sn${}_{0.4}$Te

Abstract

Discovery of exotic phases of matter from the topologically non-trivial systems not only makes the research on topological materials more interesting but also enriches our understanding of the fascinating physics of such materials. Pb${}_{0.6}$Sn${}_{0.4}$Te was recently shown to be a topological crystalline insulator. Here we show that by forming a mesoscopic point-contact using a normal non-superconducting elemental metal on the surface of Pb${}_{0.6}$Sn${}_{0.4}$Te a novel superconducting phase is created locally in a confined region under the point-contact. This happens while the bulk of the sample remains to be non-superconducting and the superconducting phase emerges as a nano-droplet under the point-contact. The superconducting phase shows a high transition temperature $T_c$ that varies for different point-contacts and falls in a range between 3.7 K and 6.5 K. Therefore, this Letter presents the discovery of a new superconducting phase on the surface of a topological crystalline insulator and the discovery is expected to shed light on the mechanism of induced superconductivity in topologically non-trivial systems in general.

arXiv commentThe submission contains 22 pages including supplementary material. The main text contains 3 figures, 36 references and supplementary material contains 11 figures and one table

References in corpus (28)

• Topological Insulators
• Topological insulators and superconductors
• Superconducting proximity effect and Majorana fermions at the surface of a topological insulator
• Topological Crystalline Insulators
• Search for Majorana fermions in superconductors
• Topological Crystalline Insulators in the SnTe Material Class
• Superconductivity in CuxBi2Se3 and its implications for pairing in the undoped topological insulator
• Introduction to topological superconductivity and Majorana fermions
• Topological Crystalline Insulators and Topological Superconductors: From Concepts to Materials
• A topological crystalline insulator (TCI) phase via topological phase transition and crystalline mirror symmetry
• Topological Superconductivity in CuxBi2Se3
• Observation of topological order in a Superconducting doped topological insulator (based on the Bi2Se3 class)
• Spin-filtered Edge States with an Electrically Tunable Gap in a Two-Dimensional Topological Crystalline Insulator
• Bulk superconducting phase with a full energy gap in the doped topological insulator Cu_xBi_2Se_3
• Observation of Dirac node formation and mass acquisition in a topological crystalline insulator
• The role of critical current on point contact Andreev Reflection spectrum between a normal metal and a superconductor
• Unconventional Superconductivity at Mesoscopic Point-contacts on the 3-Dimensional Dirac Semi-metal Cd${}_3$As${}_2$
• Evidence for massive bulk Dirac Fermions in Pb${}_{1-x}$Sn${}_x$Se from Nernst and thermopower experiments
• Electrochemical synthesis and superconducting phase diagram of Cu_xBi2Se3
• Dirac mass generation from crystal symmetry breaking on the surfaces of topological crystalline insulators
• Superconductivity in the doped topological insulator Cu${}_x$Bi${}_2$Se${}_3$ under high pressure
• Superconductivity and non-metallicity induced by doping the topological insulators Bi2Se3 and Bi2Te3
• Enhanced superconducting pairing interaction in indium-doped tin telluride
• Unconventional superconductivity in CuxBi2Se3
• Mapping the unconventional orbital texture in topological crystalline insulators
• Fermiology of Strongly Spin-Orbit Coupled Superconductor Sn1-xInxTe and its Implication to Topological Superconductivity
• Superconducting properties of the In substituted Topological Crystalline Insulator, SnTe
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Cited by in corpus (11)

• Conventional Superconductivity in Type II Dirac Semimetal PdTe${}_2$
• Mesoscopic superconductivity and high spin polarization coexisting at metallic point contacts on the Weyl semimetal TaAs
• Experimental search for the origin of low-energy modes in topological materials
• Topological properties of multilayers and surface steps in the SnTe material class
• Electronic structure of the surface superconducting Weyl semimetal PtBi${}_2$
• Discovery of highly spin-polarized conducting surface states in the strong spin-orbit coupling semiconductor Sb${}_2$Se${}_3$
• A modular point contact spectroscopy probe for sub-Kelvin applications
• Tip-induced Superconductivity
• Role of Hund's splitting in electronic phase competition in ${\mathrm{Pb}}_{1-x}{\mathrm{Sn}}_x\mathrm{Te}$
• Competing effects of Hund's splitting and symmetry-breaking perturbations on electronic order in Pb${}_{1-x}$Sn${}_x$Te
• Chiral $p-$wave superconductivity in Pb${}_{1-x}$Sn${}_x$Te: signatures from bound-state spectra and wavefunctions