Pressure-induced reemergence of superconductivity in topological insulatorSr0.065Bi2Se3

Abstract

The recent-discovered Sr x Bi 2 Se 3 superconductor provides an alternative and ideal material base for investigating possible topological superconductivity. Here, we report that in Sr 0.065 Bi 2 Se 3 , the ambient superconducting phase is gradually depressed upon the application of external pressure.At high pressure, a second superconducting phase emerges at above 6 GPa, with a maximum T c value of ∼8.3 K. The joint investigations of the high-pressure synchrotron x-ray diffraction and electrical transport properties reveal that the re-emergence of superconductivity in Sr 0.065 Bi 2 Se 3 is closely related to the structural phase transition from ambient rhombohedral phase to highpressure monoclinic phase around 6 GPa, and further to another high-pressure tetragonal phase above 25 GPa.

High-pressure study of the basal-plane anisotropy of the upper critical field of the topological superconductor SrxBi2Se3

“…We remark that the value p c = 1.1 GPa reported in Ref. 22 most likely underestimates p c as it is based on the extrapolation of T c (p) from temperatures above 2 K only. In the case of Cu x Bi 2 Se 3 the critical pressure is estimated to be a factor 2 larger than in the Sr doped case, p c ∼ 6.3 GPa 25 .…”

Pressure-induced superconductivity in MoP

“…[22][23][24][25] To date, two viable avenues to access TSC have been demonstrated, i.e., either doping or pressurizing TI, TDS, and TWS. [26][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42][43] However, the topologically nontrivial nature of the doping-and pressure-induced superconductivity is under heavy debate yet. Pressure, modifying the crystal structure and electronic band structure in a continuously controllable fashion, is a clean and efficient thermodynamic parameter in tuning the physical properties of topological quantum matter.…”

“…Pressure, modifying the crystal structure and electronic band structure in a continuously controllable fashion, is a clean and efficient thermodynamic parameter in tuning the physical properties of topological quantum matter. [36][37][38][39][40][41][42][43][44] Here, via high-pressure electrical transport and synchrotron X-ray diffraction measurements with the aid of theoretical calculations, we propose that the pressurized MoP is a promising candidate of TSC.…”

Effect of the type-I to type-II Weyl semimetal topological transition on superconductivity

“…It was discovered recently that, while parameters of the system (the electron -phonon coupling, Debye frequency Ω) between two structural phase transitions smoothly depend on a pressure, the tilt parameter is very sensitive to a stress 15,21 . Our result might provide an explanation of a spike in dependence of T c on pressure in single crystals observed in many superconducting semi-metals [26][27][28] . The experimental situation is not unambiguous.…”

“…In intercalated Sr 0.065 Bi 2 Se 3 single crystal 26 considered to be a pure material ambient weak superconductivity first is suppressed, but at high pressure of 6GP a reappears and reaches relatively high T c of 10K that persists till 80GP a. The increase is not gradual, but rather abrupt in the region of 15GP a 26 . Superconductivity in similar TI compounds 27,28 , 36 Bi 2 Se 3 , Bi 2 T e 3 and 3D Weyl semi-metal 29 Hf T e 5 were also studied experimentally.…”