title: Optical lattice polarization effects on hyperpolarizability of atomic clock transitions.
abstract: The light-induced frequency shift due to hyperpolarizability (i.e., terms of second-order in intensity) is studied for a forbidden optical transition, J = 0 --> J = 0. A simple universal dependence on the field ellipticity is obtained. This result allows minimization of the second-order light shift with respect to the field polarization for optical lattices operating at a magic wavelength (at which the first-order shift vanishes). We show the possibility for the existence of a magic elliptical polarization, for which the second-order frequency shift vanishes. The optimal polarization of the lattice field can be either linear, circular, or magic elliptical. The obtained results could improve the accuracy of lattice-based atomic clocks.
authors.affiliation: Institute of Laser Physics SB RAS, Novosibirsk 630090, Russia.
authors.forename: A V
authors.initials: AV
authors.lastname: Taichenachev
authors.forename: V I
authors.initials: VI
authors.lastname: Yudin
authors.forename: V D
authors.initials: VD
authors.lastname: Ovsiannikov
authors.forename: V G
authors.initials: VG
authors.lastname: Pal'chikov