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Physical Review B

Hyperfine structure and homogeneous broadening in Pr3+:KY(WO4)2

H. L. Xu, M. Nilsson, S. Ohser, N. Rauhut, Stefan Kröll, Magdalena Aguiló, Francesc Dı́az

Published Dec 30, 2004• 8 citations
Publisher

Abstract

As part of a search for suitable materials for coherent quantum operations, relaxation times and hyperfine structure of the $^{1}D_{2}(1)\text{\ensuremath{-}}^{3}H_{4}(1)$ transition in ${\mathrm{Pr}}^{3+}:\mathrm{KY}{({\mathrm{WO}}_{4})}_{2}$ (0.29 at. %) at 4 K have been obtained using photon-echo and spectral hole burning techniques. The homogeneous linewidth and the effect of excitation-induced dephasing were measured using two-pulse photon-echo techniques. Linewidths of $23.4\ifmmode\pm\else\textpm\fi{}1.0$ and $17.6\ifmmode\pm\else\textpm\fi{}0.9\phantom{\rule{0.3em}{0ex}}\mathrm{kHz}$ were obtained in the absence and presence of an external magnetic field of about 9 mT. The radiative lifetime $({T}_{1})$ of the $^{1}D_{2}$ state was measured to be $43\ifmmode\pm\else\textpm\fi{}2\phantom{\rule{0.3em}{0ex}}\ensuremath{\mu}\mathrm{s}$ using time-resolved laser-induced fluorescence and three-pulse photon-echo measurements. The transmission hole spectra were measured and directly yielded the quadrupole level splitting in the $^{1}D_{2}$ ($3.77\ifmmode\pm\else\textpm\fi{}0.03$ and $4.58\ifmmode\pm\else\textpm\fi{}0.04\phantom{\rule{0.3em}{0ex}}\mathrm{MHz}$) and $^{3}H_{4}$ ($17.1\ifmmode\pm\else\textpm\fi{}0.1$ and $33.2\ifmmode\pm\else\textpm\fi{}0.3\phantom{\rule{0.3em}{0ex}}\mathrm{MHz}$) states. The spectral hole lifetime due to population redistribution between the ground-state nuclear levels was also determined to be $70\ifmmode\pm\else\textpm\fi{}10\phantom{\rule{0.3em}{0ex}}\mathrm{ms}$. A strong dipole-dipole interaction observed in this crystal opens for potential applications in quantum computing schemes for performing quantum logic operations, but the short dephasing time makes it less useful in data storage applications.

DOI
10.1103/physrevb.70.214115

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We studied the hyperfine structure and hyperfine coherent properties of the ${^{3}\text{H}}_{4}(0)\ensuremath{\rightarrow}{^{1}\text{D}}_{2}(0)$ transition of Pr3+{\text{Pr}}^{3+}Pr3+ ions in a tungstate single crystal La2(WO4)3{\text{La}}_{2}{({\text{WO}}_{4})}_{3}La2​(WO4​)3​ by hole-burning and photon-echo techniques. This work is motivated by the search of an efficient three level $\ensuremath{\Lambda}$ 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 3H4(0){^{3}\text{H}}_{4}(0)3H4​(0) ground state and in the 1D2(0){^{1}\text{D}}_{2}(0)1D2​(0) excited state is obtained. The hyperfine splittings are thus ordered: 24.6 and 14.9 MHz for the 3H4(0){^{3}\text{H}}_{4}(0)3H4​(0) level and 5.0 and 7.3 MHz for the 1D2(0){^{1}\text{D}}_{2}(0)1D2​(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 $57\ifmmode\pm\else\textpm\fi{}2$ and $1.25\ifmmode\pm\else\textpm\fi{}0.1\text{ }\text{kHz}$, respectively.
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