Muonium Centers in Crystalline Si and Ge under Illumination

Abstract

The charged state of implanted positive muons, ${\mathrm{Mu}}^{\ifmmode\pm\else\textpm\fi{}}$, formed at high temperatures undergoes fast spin relaxation in both Si and Ge under illumination due to a cyclic charge-exchange reaction with photoinduced carriers. In Si, the neutral tetrahedral interstitial muonium state (${\mathrm{Mu}}_{T}^{0}$) also collides effectively with carriers to induce reaction, while in Ge the neutral state is unreactive. In particular, in Si at low temperatures, the ${\mathrm{Mu}}_{\mathrm{BC}}^{0}$ center is rapidly converted into bond center muonium (${\mathrm{Mu}}_{T}^{0}$) with supervening fast spin relaxation under illumination.