Superconductivity in Topological Insulator Sb2Te3 Induced by Pressure

Abstract

Topological superconductivity is one of most fascinating properties of topological quantum matters that was theoretically proposed and can support Majorana Fermions at the edge state. Superconductivity was previously realized in a Cu-intercalated Bi2Se3 topological compound or a Bi2Te3 topological compound at high pressure. Here we report the discovery of superconductivity in the topological compound Sb2Te3 when pressure was applied. The crystal structure analysis results reveal that superconductivity at a low-pressure range occurs at the ambient phase. The Hall coefficient measurements indicate the change of p-type carriers at a low-pressure range within the ambient phase, into n-type at higher pressures, showing intimate relation to superconducting transition temperature. The first principle calculations based on experimental measurements of the crystal lattice show that Sb2Te3 retains its Dirac surface states within the low-pressure ambient phase where superconductivity was observed, which indicates a strong relationship between superconductivity and topology nature.

Pressure-induced semiconducting to metallic transition in multilayered molybdenum disulphide

“…The DAC technique coupled with a hydrostatic pressure medium (Fig. 1b) has been shown to be effective in elucidating the electrical, vibrational, optical and structural properties of a plethora of materials 21,[23][24][25] . The optically transparent window of the diamond allows us to conduct a series of in situ highpressure experiments including accurate pressure calibration from ruby fluorescence, electrical transport measurements and optical Raman and synchrotron X-ray diffraction (XRD) spectroscopy 26 , leading to the observation of S-M transition in multilayered MoS 2 at high pressures.…”

“…Furthermore, previous theoretical studies have suggested that an iso-structural semiconducting to metallic (S-M) transition in multilayered MoS 2 can be induced by pressure or strain [18][19][20] . Despite the broad interest in this phenomenon in layered nanomaterials, previous experimental results only reported a limited reduction in the electrical resistance 17,[21][22][23] with no clear evidence for the pressureinduced S-M transition.…”

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

“…The linear temperature dependence of H c2 in Figure 3b is actually very interesting. It may come from a two-band Fermi surface topology as in MgB 2 , [35][36][37] or an unconventional superconducting state as in heavy-fermion compound UBe 13 . 38 11,[39][40][41] We notice that no superconductivity was observed up to 13.43 GPa in an earlier pressure study of Cd 3 As 2 single crystal.…”

“…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 .…”