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Muonium as a shallow center in GaN

K. Shimomura·R. Kadono·K. Ohishi·M. Mizuta·M. Saito·K. H. Chow·B. Hitti·R. L. Lichti
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Abstract

A paramagnetic muonium (Mu) state with an extremely small hyperfine parameter was observed for the first time in single-crystalline GaN below 25 K. It has a highly anisotropic hyperfine structure with axial symmetry along the [0001] direction, suggesting that it is located either at a nitrogen-antibonding or a bond-centered site oriented parallel to the c-axis. Its small ionization energy (=< 14 meV) and small hyperfine parameter (--10^{-4} times the vacuum value) indicate that muonium in one of its possible sites produces a shallow state, raising the possibility that the analogous hydrogen center could be a source of n-type conductivity in as-grown GaN.

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K. Shimomura, R. Kadono, K. Ohishi, M. Mizuta, M. Saito, K. H. Chow, B. Hitti, R. L. Lichti. 2004-02-05. Muonium as a shallow center in GaN. https://doi.org/10.1103/physrevlett.92.135505

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