We determine the local structure of isolated positively charged muonium (${\mathrm{Mu}}^{+}$) in heavily doped $p$-type GaAs based on muon level crossing resonance and zero applied field muon spin depolarization data. These measurements provide the first direct experimental confirmation that ${\mathrm{Mu}}^{+}$, and by analogy ${\mathrm{H}}^{+}$, is located within a stretched Ga-As bond. The distances between ${\mathrm{Mu}}^{+}$ and the nearest neighbor Ga and As atoms are estimated to be $1.83\pm 0.10\AA$ and $1.76\pm 0.10\AA$, respectively. These results are compared to existing theoretical calculations on the structure of hydrogen in GaAs and additionally provide data on the induced electric field gradients.

• Received 15 May 2005

DOI:https://doi.org/10.1103/PhysRevLett.95.086404