Munir Riffat, Siddiquee K A M Hasan, Dissanayake Charuni, Hu Xinzhe, Takano Yasumasa, Choi Eun Sang, Nakajima Yasuyuki
Department of Physics, University of Central Florida, Orlando, Florida 32816, United States of America.
Department of Physics, University of Florida, Gainesville, Florida 32611, United States of America.
J Phys Condens Matter. 2021 May 10;33(23). doi: 10.1088/1361-648X/abf386.
We report superconductivity in SnNbSe, a topological nodal-line semimetal candidate with a noncentrosymmetric crystal structure. The superconducting transition temperatureof this compound is extremely sensitive to Sn concentrationand Se deficiency, 5.0 K for SnNbSeand 8.6 K for SnNbSeand SnNbSe. In all samples, the temperature dependence of the upper critical field() differs from the prediction of the Werthamer-Helfand-Hohenberg theory. While the zero-temperature value of the in-plane upper critical field of SnNbSewith the higheris lower than the BCS Pauli paramagnetic limit, that of the lowersample exceedsby a factor of ∼2. Our observations suggest that a possible odd-parity contribution dominates the superconducting gap function of SnNbSe, and it can be fine-tuned by the Sn concentration and Se deficiency.
我们报道了SnNbSe中的超导性，SnNbSe是一种具有非中心对称晶体结构的拓扑节线半金属候选材料。该化合物的超导转变温度对Sn浓度和Se缺陷极为敏感，SnNbSe的转变温度为5.0 K，SnNbSe和SnNbSe的转变温度为8.6 K。在所有样品中，上临界场（）的温度依赖性与韦特哈默-赫尔方德-霍亨贝格理论的预测不同。虽然具有较高的SnNbSe的面内上临界场的零温度值低于BCS泡利顺磁极限，但较低样品的该值超过该极限约2倍。我们的观察结果表明，一种可能的奇宇称贡献主导了SnNbSe的超导能隙函数，并且它可以通过Sn浓度和Se缺陷进行微调。
