Dong Qing, Pan Jie, Li Shujia, Fang Yuqiang, Lin Tao, Liu Shuang, Liu Bo, Li Quanjun, Huang Fuqiang, Liu Bingbing
State Key Laboratory of Superhard Materials, Jilin University, Changchun, 130012, China.
State Key Laboratory of High-Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai, 200050, China.
Adv Mater. 2022 Mar;34(9):e2103168. doi: 10.1002/adma.202103168. Epub 2022 Jan 27.
Pressure has always been an effective method for uncovering novel phenomena and properties in condensed matter physics. Here, an electrical transport study is carried on 2H-TaS up to ≈208 GPa, and an unexpected superconducting state (SC-II) emerging around 86.1 GPa with an initial critical temperature (T ) of 9.6 K is found. As pressure increases, the T enhances rapidly and reaches a maximum of 16.4 K at 157.4 GPa, which sets a new record for transition metal dichalcogenides (TMDs). The original superconducting state (SC-I) is found to be re-enhanced above 100 GPa after the recession around 10 GPa, and coexists with SC-II to the highest pressure applied in this work. In situ high-pressure X-ray diffraction and Hall effect measurements reveal that the occurrence of SC-II is accompanied by a structural modification and a concurrent enhancement of hole carrier density. The new high-T superconducting state in 2H-TaS can be attributed to the change of the electronic states near the Fermi surface, owing to pressure-induced interlayer modulation. It is the first time finding this remarkable superconducting state in TMDs, which not only brings a new broad of perspective on layered materials but also expands the field of pressure-modified superconductivity.
压力一直是揭示凝聚态物理中新颖现象和性质的有效方法。在此，对2H-TaS进行了高达约208 GPa的电输运研究，发现了一种意外的超导态（SC-II），其在约86.1 GPa时出现，初始临界温度（Tc）为9.6 K。随着压力增加，Tc迅速升高，并在157.4 GPa时达到16.4 K的最大值，这为过渡金属二硫属化物（TMDs）创造了新纪录。发现原始超导态（SC-I）在约10 GPa处衰退后，在100 GPa以上重新增强，并与SC-II共存至本工作所施加的最高压力。原位高压X射线衍射和霍尔效应测量表明，SC-II的出现伴随着结构转变以及空穴载流子密度的同时增加。2H-TaS中这种新的高温超导态可归因于压力诱导的层间调制导致费米表面附近电子态的变化。这是首次在TMDs中发现这种显著的超导态，这不仅为层状材料带来了新的广阔视角，也扩展了压力调制超导性的领域。
