PHYSICAL REVIEW B, cilt.78, sa.15, 2008 (SCI-Expanded)
By using photoexcitation, we unambiguously establish that the well-known diamagnetic muonium spin precession signal in Ge is in fact due to two diamagnetic states. Their temperature dependences are studied up to room temperature. The signal due to one of these states is strongly influenced by the photoexcited carriers while the other is not. The identification of these two centers is discussed.