Metastable Shallow Muonium States in Solid Nitrogen

We recently measured detailed QLCR spectra in solid nitrogen that can be described well using Path Integral Molecular Dynamics (PIMD) to model quantum delocalisation of the muon and its effect on the electric field gradient at the neighbouring nitrogen sites, an important factor determining the QLCR spectrum. During these QLCR studies of the diamagnetic states we discovered additional new metastable paramagnetic states with ALC resonances having weak HFC of order 4 MHz. This relatively weak coupling is reminiscent of the shallow donor muonium states found in some semiconductors, e.g. CdS and ZnO, which have sub MHz HFC. The new N2 states are the first examples of shallow muonium states outside the semiconductor field. TF muSR and ALC will be used to fully characterize these states and their lifetimes. PIMD will then be used for modelling these new delocalised paramagnetic states