Spin-lattice relaxation of spin pairs in CdSe:Mn by the Dzyaloshinski-Moriya exchange interaction

We report a quantitative study of the spin-lattice relaxation of ${\mathrm{Mn}}^{2+}$ pairs in CdSe:Mn. We show that the antisymmetric exchange D⋅${\mathbf{S}}_1$×${\mathbf{S}}_2$ is the dominant mechanism of the spin-pair relaxation. Two relaxation times are observed, which are attributed to two classes of pairs with different effective coupling ${\mathit{D}}_{\mathrm{eff}}$ due to different orientation of D with respect to magnetic field B. The measured D=0.24±0.1 K agrees with theoretical calculations.