周期结构的晶格振动和分子的振动或转动谱,可以看作材料的特征指纹,拉曼散射正是探测这些振动的非常灵敏和有效的技术,因此它已经被广泛地应用到基础研究和工业生产的各个方面.而原则上,通过固体中的自由载流子或自旋与光的非弹性散射过程,人们也可以获得关于电子和磁激发的重要信息.文章对电子和磁的拉曼散射基本概念作了简要介绍,并对一些关联电子体系中的拉曼实验作了简要综述.特别是在非常规超导中,拉曼散射在确定超导能隙的大小和各向异性以及配对对称性等方面发挥了独特的作用.
Raman scattering is a very sensitive and effective probe for measuring lattice vibrations in periodic structures and the vibrations or rotations of molecules; the spectra obtained are considered the fingerprint of a specific substance. Today,Raman spectroscopy is extensively employed in fundamental research and industry. In principle,one can also obtain valuable information about electronic and magnetic excitations from the process of inelastic light scattering by free carriers or spins in a solid. This paper gives a brief review of the basic concepts and experiments on electronic and magnetic Raman scattering in various correlated electron systems,especially in unconventional superconductors where the superconducting gap size,anisotropy,and pairing symmetry can be uniquely determined by Raman spectroscopy.