Barber Z W, Stalnaker J E, Lemke N D, Poli N, Oates C W, Fortier T M, Diddams S A, Hollberg L, Hoyt C W, Taichenachev A V, Yudin V I
National Institute of Standards and Technology, 325 Broadway, Boulder, Colorado 80305, USA.
Phys Rev Lett. 2008 Mar 14;100(10):103002. doi: 10.1103/PhysRevLett.100.103002. Epub 2008 Mar 11.
We present an experimental study of the lattice-induced light shifts on the (1)S(0) --> (3)P(0) optical clock transition (nu(clock) approximately 518 THz) in neutral ytterbium. The "magic" frequency nu(magic) for the 174Yb isotope was determined to be 394 799 475(35) MHz, which leads to a first order light shift uncertainty of 0.38 Hz. We also investigated the hyperpolarizability shifts due to the nearby 6s6p(3)P(0) --> 6s8p(3)P(0), 6s8p(3)P(2), and 6s5f(3)F(2) two-photon resonances at 759.708, 754.23, and 764.95 nm, respectively. By measuring the corresponding clock transition shifts near these two-photon resonances, the hyperpolarizability shift was estimated to be 170(33) mHz for a linear polarized, 50 microK deep, lattice at the magic wavelength. These results indicate that the differential polarizability and hyperpolarizability frequency shift uncertainties in a Yb lattice clock could be held to well below 10(-17).
我们展示了一项关于中性镱中（1）S（0）→（3）P（0）光钟跃迁（ν（时钟）约为518太赫兹）上晶格诱导光频移的实验研究。174Yb同位素的“魔术”频率ν（魔术）被确定为394799475（35）兆赫兹，这导致一阶光频移不确定度为0.38赫兹。我们还研究了分别在759.708、754.23和764.95纳米处，由于附近的6s6p（3）P（0）→6s8p（3）P（0）、6s8p（3）P（2）和6s5f（3）F（2）双光子共振引起的超极化率频移。通过测量这些双光子共振附近相应的时钟跃迁频移，对于在魔术波长处线性极化、深度为50微开尔文的晶格，超极化率频移估计为170（33）毫赫兹。这些结果表明，镱晶格钟中的微分极化率和超极化率频移不确定度可以保持在远低于10^(-17)的水平。
