Optical Lattice Induced Light Shifts in an Yb Atomic Clock

We present an experimental study of the lattice-induced light shifts on the optical clock transition () in neutral ytterbium. The “magic” frequency for the isotope was determined to be , which leads to a first order light shift uncertainty of 0.38 Hz. We also investigated the hyperpolarizability shifts due to the nearby , , and 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, 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 .