Hyperfine structure and hyperfine coherent properties of praseodymium in single-crystalline La_2(WO_4)_3 by hole-burning and photon-echo techniques

摘要

We studied the hyperfine structure and hyperfine coherent properties of the ~3H_4(0)→ ~1D_2(0) transition of Pr~(3+) ions in a tungstate single crystal La_2(WO_4)_3 by hole-burning and photon-echo techniques. This work is motivated by the search of an efficient three level A system in this new compound with which we could build up a quantum memory. By nonconventional hole-burning experiments, the ordering of the hyperfine splittings in the ~3H_4(0) ground state and in the ~1d_2(0) excited state is obtained. The hyperfine splittings are thus ordered: 24.6 and 14.9 MHz for the ~3H_4(0) level and 5.0 and 7.3 MHz for the ~1D_2(0) level. The relative and absolute transition strengths of individual hyperfine transitions are determined by comparing absorption strengths and by measuring the Rabi flopping frequency as the transition is coherently driven. Free induction and Raman echo decays give inhomogeneous and homogeneous hyperfine linewidths of 57±2 and 1.25±0.1 kHz, respectively.