Emergence of intrinsic superconductivity below 1.178 K in the topologically non-trivial semimetal state of CaSn3. (4th April 2019)

• Record Type: Journal Article
• Authors: Zhu, Y L; Hu, J; Womack, F N; Graf, D; Wang, Y; Adams, P W; Mao, Z Q
• Is Part Of: Journal of physics. Volume 31:Number 24(2019)
• Publication Date: 2019-04-04
• Subjects: superconductivity -- topological materials -- de Haas–van Alphen oscillation; Condensed matter -- Periodicals; Matière condensée -- Périodiques; Vaste stoffen; Vloeistoffen; Natuurkunde; Electronic journals; Computer network resources; 530.4105
• DOI: 10.1088/1361-648X/ab0f0d
• Languages: English
• ISSNs: 0953-8984

Abstract

Abstract: Topological materials which are also superconducting are of great current interest, since they may exhibit a non-trivial topologically-mediated superconducting phase. Although there have been many reports of pressure-tuned or chemical-doping-induced superconductivity in a variety of topological materials, there have been few examples of intrinsic, ambient pressure superconductivity in a topological system having a stoichiometric composition. Here, we report that the pure intermetallic CaSn3 not only exhibits topological fermion properties, but also has a superconducting phase at ~1.178 K under ambient pressure. The topological fermion properties, including the nearly zero quasi-particle mass and the non-trivial Berry phase accumulated in cyclotron motions, were revealed from the de Haas–van Alphen (dHvA) quantum oscillation studies of this material. Although CaSn3 was previously reported to be superconducting with T c = 4.2 K, our studies show that the T c = 4.2 K superconductivity is extrinsic and caused by Sn on the degraded surface, whereas its intrinsic bulk superconducting transition occurs at 1.178 K. These findings make CaSn3 a promising candidate for exploring new exotic states arising from the interplay between non-trivial band topology and superconductivity, e.g. topological superconductivity (TSC).