报告题目：Absenceof conventional room temperature superconductivity at high pressure in carbondoped H3S

报告人：王天淳

报告时间：2022年3月1日上午10:00

报告地点：必赢电子游戏网站中心校区唐敖庆楼B520

报告摘要：

Recently,it has been reported that room-temperature superconductivity with Tc~ 280 K emerges in carbonaceous sulfur hydride (C-S-H) systems under highpressure up to 270 GPa [1]. Since their atomic configuration isstill not determined, we explore a variety of crystal structures in a C-S-Hconvex hull and discuss the stability of candidate structures of C-S-H ternarycompounds [2].

In this study, weshow that the same theoretical tools that successfully explain other hydridesystems under pressure seem to be at odds with the recently claimedconventional room-temperature superconductivity of carbonaceous sulfur hydride.We support our conclusions with (i) the absence of a dominant low-enthalpystoichiometry and crystal structure in the ternary phase diagram. (ii) Only thethermodynamics of C-doping phases appears to be marginally competing inenthalpy against H3S. (iii) Accurate results of the transition temperaturegiven by ab initio Migdal-Eliashberg calculations [3] differby more than 110 K from recent theoretical claims explaining thehigh-temperature superconductivity in carbonaceous hydrogen sulfide. Anunconventional mechanism of superconductivity or a breakdown of currenttheories in this system is possibly behind the disagreement.

[1]E. Snider, N. Dasenbrock-Gammon, R. Mcbride, M. Debessai, H. Vindana, K. Vencatasamy,K. V. Lawler, A. Salamat and R. P. Dias, Nature 586,373-377 (2020)

[2]T. Wang, M. Hirayama, T. Nomoto, T. Koretsune, R. Arita, and José A.Flores-Livas, Phys.Rev. B 104, 064510 (2021)

[3]T. Wang, T. Nomoto, Y. Nomura, H. Shinaoka, J. Otsuki, T. Koretsune and R.Arita, Phys. Rev. B 102, 134503 (2020)

报告人简介:

王天淳，2018年本科毕业于复旦大学物理系。2018年至今在东京大学工学系物理工学研究科攻读博士学位。2018年起加入导师Ryotaro Arita教授的课题组。主要研究方向为应用第一性原理计算方法对材料性质进行模拟和预测。目前的研究课题包括Migdal-Eliashberg理论框架下的超导温度计算方法开发，以及对高压氢化物超导体系的计算和预测。

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