2015/12/30 by P. Arevalo-López, Rodolfo E. López-Romero, R. E. López-Romero +4
Materials Science · Physics and Astronomy · #Advanced Condensed Matter Physics #FOS: Physical sciences #Iron-based superconductors research #Superconductivity (cond-mat.supr-con) #Topological Materials and Phenomena #cond-mat.supr-con
paper · pdf · doi:10.48550/arxiv.1512.09098
These are our new superconducting studies in single crystal of a topological insulator observed by proximity effect induced with Pb
arxiv created 2015/12/30 · openalex publication_date 2015/12/30 · arxiv updated 2015/12/31 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
Some topological insulators become superconducting when doped with Cu and Pd. Superconductivity in a non-superconductor may be induced by proximity effect: i.e. Contacting a non-superconductor with a superconductor. The superconducting macroscopic wave function will induce electronic pairing into the normal compound. In the simplest topological insulator, Bi2Se3, superconductivity may be induced with Pb. We studied with point contact junctions formed by contacting Bi2Se3 crystals and Pb, glued and pressed with silver paste and/or applying low heat to the Pb to improve the contact. Junctions were formed with a thin tungsten plated gold W(Au) wire as one electrode, and the other Bi2Se3 and Pb. We study the characteristics of the electron coupling; the transition temperature,TC, evolution with temperature of the energy gap, Δ, and 2Δ/KBTC ratio. The superconductor Bi2Se3-Pb behaves different as explained in the classical BCS theory. In BCS a superconductor is only weak or strong coupled, depending on the electronic interaction that form the electronic condensate. This differentiation is given by the size of the mentioned ratio. BCS Typical values are 3.53 to about 4.3 for weak or strong coupling limits respectively. In this study performed in Bi2Se3-Pb we found different values to the normal ones from 10 to 23, indicating very strong limit. Those values never have been observed in other superconductor. The transition temperatures found varies from 2.7 to 7 K. This information and other results will be presented in this paper.