Operational Magic Intensity for Sr Optical Lattice Clocks

Authors
Ichiro Ushijima, Masao Takamoto, Hidetoshi Katori 

Abstract

We experimentally investigate the lattice-induced light shift by the electric-quadrupole (E2) and magnetic-dipole ($M1$) polarizabilities and the hyperpolarizability in Sr optical lattice clocks. Precise control of the axial as well as the radial motion of atoms in a one-dimensional lattice allows observing the $E2$-$M1$ polarizability difference. Measured polarizabilities determine an operational lattice depth to be $72\left(2\right)E_R$, where the total light shift cancels to the ${10}^{-19}$ level, over a lattice-intensity variation of about 30%. This operational trap depth and its allowable intensity range conveniently coincide with experimentally feasible operating conditions for Sr optical lattice clocks.

Physical Review Letters : https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.121.263202