Nakajima Yasuyuki, Hu Rongwei, Kirshenbaum Kevin, Hughes Alex, Syers Paul, Wang Xiangfeng, Wang Kefeng, Wang Renxiong, Saha Shanta R, Pratt Daniel, Lynn Jeffrey W, Paglione Johnpierre
Center for Nanophysics and Advanced Materials, Department of Physics, University of Maryland, College Park, MD 20742, USA.
NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA.
Sci Adv. 2015 Jun 5;1(5):e1500242. doi: 10.1126/sciadv.1500242. eCollection 2015 Jun.
We report superconductivity and magnetism in a new family of topological semimetals, the ternary half-Heusler compound RPdBi (R: rare earth). In this series, tuning of the rare earth f-electron component allows for simultaneous control of both lattice density via lanthanide contraction and the strength of magnetic interaction via de Gennes scaling, allowing for a unique tuning of the normal-state band inversion strength, superconducting pairing, and magnetically ordered ground states. Antiferromagnetism with ordering vector (½,½,½) occurs below a Néel temperature that scales with de Gennes factor dG, whereas a superconducting transition is simultaneously supressed with increasing dG. With superconductivity appearing in a system with noncentrosymmetric crystallographic symmetry, the possibility of spin-triplet Cooper pairing with nontrivial topology analogous to that predicted for the normal-state electronic structure provides a unique and rich opportunity to realize both predicted and new exotic excitations in topological materials.
我们报道了一类新型拓扑半金属——三元半赫斯勒化合物RPdBi（R：稀土元素）中的超导性和磁性。在这个系列中，通过调整稀土f电子成分，可以同时通过镧系收缩控制晶格密度，并通过德热纳标度控制磁相互作用强度，从而实现对正常态能带反转强度、超导配对以及磁有序基态的独特调控。具有有序矢量（½,½,½）的反铁磁性出现在与德热纳因子dG相关的奈尔温度以下，而超导转变则随着dG的增加而同时受到抑制。由于超导性出现在具有非中心对称晶体对称性的系统中，类似于正常态电子结构所预测的具有非平凡拓扑的自旋三重态库珀对的可能性，为在拓扑材料中实现预测的和新的奇异激发提供了独特而丰富的机会。
