Unusual sulfur isotope effect and extremely high critical temperature in H3S superconductor

Abstract

Recent experiments have set a new record for the transition temperature at which a material (hydrogen sulfide, H3S) becomes superconducting. Moreover, a pronounced isotope shift of TC in D3S is evidence of an existence of phonon-mediated pairing mechanism of superconductivity that is consistent with the well established Bardeen-Cooper-Schrieffer scenario. Herein, we reported a theoretical studies of the influence of the substitution of 32S atoms by the heavier isotopes 33S, 34S and 36S on the electronic properties, lattice dynamics and superconducting critical temperature of H3S. There are two equally fundamental results presented in this paper. The first one is an anomalous sulfur-derived superconducting isotope effect, which, if observed experimentally, will be subsequent argument that proves to the classical electron-phonon interaction. The second one is fact that critical temperature rise to extremely high value of 242 K for H336S at 155 GPa. This result brings us closer to the room temperature superconductivity.

High-T c superconductivity in H3S: pressure effects on the superconducting critical temperature and Cooper pair distribution function

“…We note that obtaining a good agreement for a specific value of T c does not necessarily imply an adequate reproduction of the tendency experimentally observed as is the case of the results reported by Nakanishi et al [16], in which, using the Allen-Dynes equation was calculated at 200 GPa a T c of 186 K with excellent agreement with the experiment, but their data reveal a positive dT c /dp, in total contradiction with the experimental behavior.…”

“…with other theoretical predictions [16,26,27]. The experimental data was reported by Einaga et al [25].…”

“…In addition, they reported at 150 GPa a T c value of 19 K below the experimental one. On the other hand, the calculations reported by Szcześniak et al [16], Flores-Livas et al [18] and Errea et al [15] show a dT c /dp ∼ −0.4 with excellent agreement with the experiment, In Fig. 4(a) In Fig.…”

“…Fig. 3 shows the pressure dependence of the superconducting critical temperature (T c ) measured [1] and calculated in this work using the FDM, and its comparison with previous theoretical reports [ [14][15][16][17][18]. On the overall, the FDM manages to reproduce the tendency of the T c experimental data as a function of pressure reported by Drozdov et al [1], it means the decrease in T c with the increase in pressure, with an important agreement in the range of 155-185 GPa.…”

Pressure effects on the electronic structure and superconductivity of(TaNb)0.67(HfZrTi)0.33high entropy alloy

“…High-pressure studies of superconducting materials have brought about the latest breakthrough in the field of superconductivity. The record-high T c of 203 K in H 3 S [1] and 250 K in LaH 10 [2] at P > 150 GPa were recently reported, and theoretical predictions show that even larger values of T c are possible [3,4]. As superconductivity in these materials is mediated by the electron-phonon interaction, recent discoveries also turned attention to the effect of extreme pressure on superconductivity in other materials, including bulk conventional superconductors.…”