Davydov Splitting of theE2Lines in AntiferromagneticCr2O3

Abstract

This Letter reports the observation of a Davydov splitting in the optical absorption spectrum of ${\mathrm{Cr}}_2$ ${\mathrm{O}}_3$. In zero external field, a transition to only one level of the Davydov pair is observed. With $H$ parallel to the $c$ axis, an additional line having a field-dependent absorption appears. The extrapolated zero-field splitting is 3.75(±0.25) ${\mathrm{cm}}^{-1\mathrm{}}$.