Muonium in Silicon and Germanium—a Deep Donor

The hyperfine splitting of muonium in Si and Ge is analyzed on various models of the dielectric properties of the medium. Muonium acts as a deep donor in Si and Ge, contrary to some earlier predictions. It is possible to give a reasonable account of the observed values of |ψ(0)|² in terms of the Reiss-Kaus cavity models, and in terms of the Walter-Cohen ε(q) calculated from the actual band structures, provided that the electron mass is taken as essentially equal to the free-electron mass. Identical results are expected for interstitial atomic hydrogen.