Multiphonon Radiationless Relaxationless in Rare-Earth Dopant Ions

Konstantin K. Pukhov, Tasoltan T. Basiev, Johann Heber +2 more

Konstantin K. Pukhov, Tasoltan T. Basiev, Francois E. Auzel +2 more

Francois E. Auzel

V. V. Svishchenko

F. Pellé, Nicole Gardant, Francois E. Auzel

Multiphonon relaxation rate saturation is observed for rare-earth-doped glasses for high excited-state densities. This behavior is analyzed in a statistical approach; a theoretical model for the microscopic process is proposed. A phonon bottleneck effect on radiationless relaxation related to an accepting-modes saturation is suggested. At high excited-state density, ions in a phonon diffusion volume simultaneously fill the accepting modes. The critical distance below which excited ions share a common phonon bath is related to the phonon diffusion length in the host and deduced from our model. The results are in good agreement with the phonon mean free path independently deduced from sound velocity, thermal conductivity, and heat capacity.

Jonathan R. Everts, Matthew C. Berrington, Rose L. Ahlefeldt +1 more

Most investigations of rare-earth ions in solids for quantum information have used crystals where the rare-earth ion is a dopant. Here, we analyze the conversion of quantum information from microwave photons to optical frequencies using crystals where the rare-earth ions, rather than being dopants, are part of the host crystal. These concentrated crystals are attractive for frequency conversion because of their large ion densities and small linewidths. We show that conversion with both high efficiency and large bandwidth is possible in these crystals. In fact, the collective coupling between the rare-earth ions and the optical and microwave cavities is large enough that the limitation on the bandwidth of the devices will instead be the spacing between magnon modes in the crystal.