重费米子超导理论和材料研究进展

Theoretical progress and material studies of heavy fermion superconductors

重费米子超导体是一类典型的强关联和非常规超导系统,超导的产生与量子临界涨落有着紧密的关系.在实际材料中,不同结构体系的重费米子超导体往往表现出非常不同的竞争序和超导性质,表明f电子的行为对材料的结构特征具有敏感依赖性.特别是最近几年的超导实验研究,表明具体材料的实际电子结构对重费米子超导的性质具有重要影响.本文将简要介绍几类典型重费米子体系的最新研究进展,并结合实际材料的强关联能带结构计算、唯象量子临界涨落特征和Eliashberg超导理论,发展新的重费米子超导唯象理论框架,为探索非常规超导的微观机理提供新的思路.

Heavy fermion superconductors belong to a special class of strongly correlated systems and unconventional superconductors.The emergence of superconductivity in these materials is closely associated with the presence of quantum critical fluctuations.Heavy fermion superconductors of different structures often exhibit distinct competing orders and superconducting phase diagrams,implying sensitive dependence of their electronic structures and pairing mechanism on the crystal symmetry.Here we give a brief introduction on recent theoretical and experimental progress in several different material families.We develop a new phenomenological framework of superconductivity combining the Eliashberg theory,a phenomenological form of quantum critical fluctuations,and strongly correlated band structure calculations for real materials.Our theory provides a unified way for systematic understanding of various heavy fermion superconductors.