1208.2848 (Thomas Middelmann et al.)

High accuracy correction of blackbody radiation shift in an optical
lattice clock    [PDF]

Thomas Middelmann, Stephan Falke, Christian Lisdat, Uwe Sterr

We have determined the frequency shift that blackbody radiation is inducing on the $5s^2$ $^1$S$_0$ -- $5s5p$ $^3$P$_0$ clock transition in strontium. Previously its uncertainty limited the uncertainty of strontium lattice clocks to $1\times10^{-16}$. Now the uncertainty associated to the black body radiation shift correction translates to $5\times 10^{-18}$ relative frequency uncertainty at room temperature. Our evaluation is based on a measurement of the differential dc-polarizability of the two clock states and on a modeling of the dynamic contribution using this value and experimental data for other atomic properties.

View original: http://arxiv.org/abs/1208.2848