【摘要】 自从在准二维铜氧化物中发现高温超导电性以来,一些类似的层状过渡金属化合物也相继被发现具有非常规超导电性.我们近来在准一维关联电子材料K2Cr3As3中观察到6.1 K超导电性,这与之前的准二维超导体明显不同.该材料的晶体结构具有由共面Cr6/2和As6/2八面体形成的[(Cr3As3)2-]∞双壁亚纳米管,此纳米管被K+离子所分隔开.此后不久,具有相同结构的Rb2Cr3As3超导体也被合成出来,形成了一个新的超导家族.本文报道了该超导家族的第三个成员,即Cs2Cr3As3.其链间距最长,并在2.2 K出现超导转变.与此前的两个成员相似,Cs2Cr3As3的正常态同样表现出具有线性电阻率的非费米液体行为.另外其上临界磁场也超过泡利顺磁极限,表明这类准一维铬基材料可能具有共同的非常规超导电性.更多还原

【Abstract】 Since the discovery of high-temperature superconductivity(SC) in quasi-two-dimensional copper oxides,a few layered compounds,which bear similarities to the cuprates,have also been found to host the unconventional SC. Our recent observation of SC at 6.1 K in correlated electron material K2Cr3As3 represents an obviously different paradigm,primarily because of its quasi-one-dimensional(Q1D) nature. The new material is structurally featured by the [(Cr3As3)2-]∞ double-walled subnano-tubes composed of face-sharing Cr6/2(As6/2) octahedron linear chains,which are well separated by the columns of K+ counterions. Later,an isostructural superconducting Rb2Cr3As3 was synthesized,thus forming a new superconducting family. Here we report the third member,Cs2Cr3As3,which possesses the largest interchain distance. SC appears below 2.2 K. Similar to the former two sister compounds,Cs2Cr3As3 exhibits a non-Fermi liquid behavior with a linear temperature dependence of resistivity in the normal state,and a high upper critical field beyond the Pauli limit as well,suggesting a common unconventional SC in the Q1 D Cr-based material.更多还原