新型4d/5d基超导体的结构和物性  

Crystal structures and physical properties of novel 4d/5d based superconductors

作　　者：宋艳鹏 陈洪祥 郭建刚[1] 陈小龙[1,2] Song Yan-Peng;Chen Hong-Xiang;Guo Jian-Gang;Chen Xiao-Long(Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China;University of Chinese Academy of Sciences, Beijing 100049, China)

机构地区：[1]中国科学院物理研究所,北京100190 [2]中国科学院大学,北京100049

出　　处：《物理学报》2018年第12期140-151,共12页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:51772322)资助的课题~~

摘　　要：在强关联电子体系中,轨道、自旋和晶格等自由度之间的相互作用一直是研究的热点.这些自由度之间的竞争和共存产生了复杂新奇的物理现象,如超导现象、量子相变、自旋有序、拓扑相变、金属绝缘转变等,这些丰富的物理现象来源于不同的有序态或量子涨落之间的竞争和耦合.自旋轨道耦合作用是指粒子的自旋角动量和轨道角动量之间的相互作用,在4d/5d基化合物中,由于电子的运动速度较快,自旋轨道耦合的效应不可忽视,可能表现出与3d基化合物不同的物性.例如,在含4d/5d过渡族金属元素的超导体中,其电子配对的机制可能不同于常规的s波Bardeen-Cooper-Schrieffer超导体.本文以几种典型的4d/5d基超导体为例,对其晶体结构和超导物性及其内在联系进行了详细论述,重点探讨了阴离子共价键强弱对晶体结构、相变和超导物性的影响,希望引起相关研究者对该类超导体的重视.The interplay among spin, orbital and lattice in a strongly-correlated electron system attracts a lot of attention in the community of condensed matter physics. The competition and collaboration of these effects result in multiple ground states, such as superconductivity, quantum criticality state, topological phase transition, metallic-insulating transition, etc. As is well known, tile spin-orbital coupling is an interaction between the spin angular moment and orbit angular moment. In quantum mechanics, the spin-orbital coupling can be described as an additional interaction in the Hamitonian. For a compound containing heavy elements, the spin-orbital interaction becomes nontrival and can influence the ground states. For instance, in 4d/5d based superconductors, the superconducting pairing mechanism might be significantly different from that of conventional Bardeen-Cooper-Schrieffer superconductor. In this paper, we will summarize the structures and physical properties of several typical 4d/5d transition metal-based superconductors and discuss the intrinsic relationship between them. Importantly, the strength of anionic covalent bonds can determine the phase transition and superconductivity, which will be highlighted here.

关 键 词：自旋轨道耦合 超导体 化学键 

分 类 号：O511.3[一般工业技术—材料科学与工程]