Center for Advanced Quantum Studies, Department of Physics, Beijing Normal University, Beijing 100875, People's Republic of China.
Rep Prog Phys. 2019 Jan;82(1):012503. doi: 10.1088/1361-6633/aaed0d. Epub 2018 Oct 31.
The presence of magnetic ions was first believed to be detrimental to superconductivity. However, unconventional superconductivity has been widely induced by doping or applying external pressure in magnetic systems such as heavy fermion, cuprate and iron-based superconductors in which magnetic fluctuations are suggested to serve as the pairing glue for Cooper pairs. The discovery of superconductivity in the magnetic compounds CrAs and MnP under high pressures has further expanded this family of superconductors and provided new platforms for investigating the interplay between magnetism and superconductivity. CrAs and MnP represent the first superconductors among the transition metal Cr- and Mn-based compounds in which the electronic states near the Fermi level are dominated by Cr/Mn 3d electrons. Shortly after their discovery, new types of Cr-based quasi-one-dimensional superconductors ACrAs and ACrAs (A [Formula: see text] K, Rb, Cs or Na) were discovered at ambient pressure. The close proximity of superconductivity to magnetic instability in these systems suggests that spin fluctuations may play crucial roles in mediating the Cooper pairing. In this article we review the basic physical properties of these novel superconductors and the progress achieved in recent studies.
磁性离子的存在最初被认为对超导性有害。然而，在诸如重费米子、铜酸盐和铁基超导体等磁性体系中，通过掺杂或施加外部压力，已经广泛诱导出非常规超导性，其中磁涨落被认为是库珀对的配对胶。在高压下 CrAs 和 MnP 等磁性化合物中发现超导性进一步扩展了这类超导体的范围，并为研究磁性和超导性之间的相互作用提供了新的平台。CrAs 和 MnP 代表了第一类过渡金属 Cr 和 Mn 基化合物中的超导体，其中费米能级附近的电子态主要由 Cr/Mn 3d 电子主导。在它们被发现后不久，在常压下就发现了新型的 Cr 基准一维超导体 ACrAs 和 ACrAs（A [Formula: see text] K、Rb、Cs 或 Na）。在这些体系中，超导性与磁不稳定性的接近表明，自旋涨落可能在介导库珀对中起着至关重要的作用。在本文中，我们综述了这些新型超导体的基本物理性质以及最近研究中取得的进展。
