Dynamical Jahn-Teller effect and fluorescence line narrowing of theA24−4T2zero-phonon transition inKZnF3:Cr

Abstract

Fluorescence-line-narrowing measurements of the ${}_{}{}^4{}_{}{}^{}\mathrm{A}_2^{}{}_{}{}^{}$ ${\mathrm{-}}^4$ ${\mathrm{T}}_2$ zero-phonon line of ${\mathrm{KZnF}}_3$:Cr are reported. The structure of the spin-orbit-split line is studied on the basis of a single-mode approximation, including Jahn-Teller coupling to tetragonal modes. The results are compared with those of other, similar systems, and the validity of the single-mode model is discussed.