Spin-phonon interactions in solids

Abstract

Phenomena associated with the coupling between the elastic and magnetic degrees of freedom in crystalline solids are considered. Nuclear and electronic spin systems in either paramagnetic or magnetically ordered configurations can couple to the acoustic vibrational modes of a solid. The several mechanisms for coupling nuclear spin systems to elastic waves in diamagnetic, metallic, and magnetically ordered media are discussed. The resonant interaction between paramagnetic impurity ions and elastic waves is outlined briefly along with application of this coupling to the phenomenon of self-induced transparency. Experimental measurements of the phase velocity of elastic waves in the anisotropic antiferromagnet MnF2 are presented. These demonstrate clearly that the rotation as well as the strain associated with an elastic shear wave can couple to spin systems in anisotropic media.