Superconductivity in Strong Spin Orbital Coupling Compound Sb2Se3

Abstract

Recently, A2B3 type strong spin orbital coupling compounds such as Bi2Te3, Bi2Se3 and Sb2Te3 were theoretically predicated to be topological insulators and demonstrated through experimental efforts. The counterpart compound Sb2Se3 on the other hand was found to be topological trivial, but further theoretical studies indicated that the pressure might induce Sb2Se3 into a topological nontrivial state. Here, we report on the discovery of superconductivity in Sb2Se3 single crystal induced via pressure. Our experiments indicated that Sb2Se3 became superconductive at high pressures above 10 GPa proceeded by a pressure induced insulator to metal like transition at ~3 GPa which should be related to the topological quantum transition. The superconducting transition temperature (TC) increased to around 8.0 K with pressure up to 40 GPa while it keeps ambient structure. High pressure Raman revealed that new modes appeared around 10 GPa and 20 GPa, respectively, which correspond to occurrence of superconductivity and to the change of TC slop as the function of high pressure in conjunction with the evolutions of structural parameters at high pressures.

Structural, Vibrational, and Electronic Study of α-As2Te3 under Compression

“…From this perspective, it is observed that the cation LEP is active in both polyhedral units of Sb2Se3, but only in one polyhedral unit of α-As 2 Te 3 ; i.e., the LEP activity of Sb in Sb 2 Se 3 is larger than that of As in α-As 2 Te 3 . This different LEP activity is a consequence that the cation LEP activity depends on the anion and increases for lighter anions as already reported elsewhere [31].…”

Pressure-induced superconductivity in the three-dimensional topological Dirac semimetal Cd3As2

“…28 The largest natural surface was determined as (112) Pressure-induced superconductivity in Dirac semimetal Cd 3 As 2 L He et al hexagonal boron nitride. 9,13,14 The sample size is about 80 × 80 μm 2 in the (112) plane, with the thickness of ∼ 10 μm. The pressure was determined by ruby fluorescence method at room temperature before and after each cooling down.…”

“…[9][10][11][12][13][14] High-pressure powder XRD measurements on Cd 3 As 2 were performed up to 17.80 GPa. In Figure 4, the XRD patterns below 2.60 GPa can be well indexed as the tetragonal phase in space group I4 1 /acd.…”

“…7,8 Under pressure, Bi 2 Te 3 , Bi 2 Se 3 , Sb 2 Te 3 and Sb 2 Se 3 become superconducting, which are also regarded as candidates for TSCs. [9][10][11][12][13][14] Note that there are debates on whether these candidates are indeed TSCs, [9][10][11][12][13][14][15][16][17] therefore further experimental works are needed to definitely identify a TSC and manipulate the Majorana fermions on its surface.…”

“…23 More interestingly, it was predicted that topological superconductivity may be achieved in Cd 3 As 2 by carrier doping, 23 but this has not been realised so far. As pressure is an effective way to induce superconductivity in TIs, [10][11][12][13][14][15] it will be very interesting to check whether superconductivity can be achieved by applying pressure on Cd 3 As 2 .…”