Anisotropy of the electronic g factors for anomalous muonium in silicon and germanium

When the electronic g factor is isotropic, one of the muon-spin-rotation (SR) frequencies of anomalous muonium is almost isotropic at a particular value of the applied magnetic field, the magic field. By measuring the field dependence of the SR frequencies around this magic field, the g-factor anisotropy g-g in Ge is found to be +0.0330(12) while that in Si is zero [+0.0002(8)] within experimental accuracy. The consequences of these results for a model of anomalous muonium are discussed in terms of the g-factor anisotropies for known defects in Si. © 1986 The American Physical Society.