Spin decoupling and line narrowing are observed for the first time in an optical transition, $^{3}H_{4}\ensuremath{\leftrightarrow}^{1}D_{2}$ of ${\mathrm{Pr}}^{3+}$ in La ${\mathrm{F}}_{3}$ at 2\ifmmode^\circ\else\textdegree\fi{}K, with use of optical free-induction decay. The $^{19}\mathrm{F}$ nuclei, when irradiated by an appropriate rf field, undergo forced precession about an effective field at the magic angle in the rotating frame. The fluctuating $^{19}\mathrm{F}$ - $^{19}\mathrm{F}$ dipolar interaction is thereby quenched and the optical linewidth drops from \ensuremath{\sim}10 to \ensuremath{\sim}2 kHz, as predicted in a theory of spin diffusion.Spin decoupling and line narrowing are observed for the first time in an optical transition, $^{3}H_{4}\ensuremath{\leftrightarrow}^{1}D_{2}$ of ${\mathrm{Pr}}^{3+}$ in La${\mathrm{F}}_{3}$ at 2\ifmmode^\circ\else\textdegree\fi{}K, with use of optical free-induction decay. The $^{19}\mathrm{F}$ nuclei, when irradiated by an appropriate rf field, undergo forced precession about an effective field at the magic angle in the rotating frame. The fluctuating $^{19}\mathrm{F}$-$^{19}\mathrm{F}$ dipolar interaction is thereby quenched and the optical linewidth drops from \ensuremath{\sim}10 to \ensuremath{\sim}2 kHz, as predicted in a theory of spin diffusion.

Physical Review LettersDec 17, 197966 citations

Narrow-line Cooling and Determination of the Magic Wavelength of Cd

Atsushi Yamaguchi, Marianna S. Safronova, Kurt Gibble +1 more

We experimentally and theoretically determine the magic wavelength of the (5s^{2})^{1}S_{0}-(5s5p)^{3}P_{0} clock transition of ^{111}Cd to be 419.88(14) and 420.1(7) nm. To perform Lamb-Dicke spectroscopy of the clock transition, we use narrow-line laser cooling on the ^{1}S_{0}-^{3}P_{1} transition to cool the atoms to 6 μK and load them into an optical lattice. Cadmium is an attractive candidate for optical lattice clocks because it has a small sensitivity to blackbody radiation and its efficient narrow-line cooling mitigates higher order light shifts. We calculate the blackbody shift, including the dynamic correction, to be fractionally 2.83(8)×10^{-16} at 300 K, an order of magnitude smaller than that of Sr and Yb. We also report calculations of the Cd ^{1}P_{1} lifetime and the ground state C_{6} coefficient.We experimentally and theoretically determine the magic wavelength of the (5s^{2})^{1}S_{0}-(5s5p)^{3}P_{0} clock transition of ^{111}Cd to be 419.88(14) and 420.1(7) nm. To perform Lamb-Dicke spectroscopy of the clock transition, we use narrow-line laser cooling on the ^{1}S_{0}-^{3}P_{1} transition to cool the atoms to 6 μK and load them into an optical lattice. Cadmium is an attractive candidate for optical lattice clocks because it has a small sensitivity to blackbody radiation and its efficient narrow-line cooling mitigates higher order light shifts. We calculate the blackbody shift, including the dynamic correction, to be fractionally 2.83(8)×10^{-16} at 300 K, an order of magnitude smaller than that of Sr and Yb. We also report calculations of the Cd ^{1}P_{1} lifetime and the ground state C_{6} coefficient.

arXiv:1909.07931Physical Review LettersSep 13, 201964 citations

Spin decoupling and line narrowing are observed for the first time in an optical transition, $^{3}H_{4}\ensuremath{\leftrightarrow}^{1}D_{2}$ of

{\mathrm{Pr}}^{3+}

in La

{\mathrm{F}}_{3}

at 2\ifmmode^\circ\else\textdegree\fi{}K, with use of optical free-induction decay. The

^{19}\mathrm{F}

nuclei, when irradiated by an appropriate rf field, undergo forced precession about an effective field at the magic angle in the rotating frame. The fluctuating

^{19}\mathrm{F}

^{19}\mathrm{F}

dipolar interaction is thereby quenched and the optical linewidth drops from \ensuremath{\sim}10 to \ensuremath{\sim}2 kHz, as predicted in a theory of spin diffusion.