Spectroscopic investigations of Pr3+:CaWO4 at liquid-helium temperatures

Abstract

Rare-earth ions doped into low nuclear-spin density host crystals provide a promising platform for quantum information storage and processing. Calcium tungstate $({\mathrm{CaWO}}_{4})$ is an attractive host crystal because it can be isotopically enriched to provide a nuclear spin free environment. Here, we report a spectroscopic investigation of the optical transitions and hyperfine transitions of praseodymium $(^{141}\mathrm{Pr}^{3+})$ doped in ${\mathrm{CaWO}}_{4}$ at liquid-helium temperatures. The hyperfine structures of the ${}^{3}{H}_{4}$(0) and ${}^{1}{D}_{2}$(0) states are determined by spectral hole burning. The results indicate that ${\mathrm{Pr}}^{3+}$:${\mathrm{CaWO}}_{4}$ is an appealing candidate for quantum memory in quantum information processing.