State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences , Shanghai 200050, China.
University of Chinese Academy of Sciences , Beijing 100049, China.
J Am Chem Soc. 2017 Apr 5;139(13):4623-4626. doi: 10.1021/jacs.7b00216. Epub 2017 Mar 23.
Since interface superconductivity was discovered at the interface between two insulating layers LaAlO and SrTiO, such interface-induced superconducting systems have been a research hotspot in superconductivity. Here, we report homogeneous interfaces formed by stacking chemically exfoliated monolayer TaS nanosheets randomly. Enhanced superconductivity of T = 3 K is observed, compared with 0.8 K of parent 2H-TaS. The measurement of heat capacity shows the increase of electronic specific-heat coefficient γ of restacked TaS nanosheets compared to parent 2H-TaS crystals. Density functional theory calculations indicate that increase and delocalization of electron states near the Fermi surface due to the homogeneous interfaces effects could account for the enhanced superconductivity.
自从在绝缘层 LaAlO 和 SrTiO 之间的界面发现了界面超导性以来，这种界面诱导超导系统一直是超导领域的研究热点。在这里，我们报告了通过随机堆叠化学剥离的单层 TaS 纳米片形成的均匀界面。与母体 2H-TaS 的 0.8 K 相比，观察到 T = 3 K 的增强超导性。比热测量表明，与母体 2H-TaS 晶体相比，重新堆积的 TaS 纳米片的电子比热系数 γ 增加。密度泛函理论计算表明，由于均匀界面效应导致费米面附近电子态的增加和离域化可以解释增强的超导性。
