Turquoise Magic Wavelength of the ${}^{87}$Sr Clock Transition

Abstract

Optical lattice clocks of fermionic strontium offer a versatile platform for probing fundamental physics and developing quantum technologies. The bivalent electronic structure of strontium gives rise to a doubly-forbidden atomic transition that is accessible due to hyperfine mixing in fermionic strontium-87, thus resulting in a sub-millihertz natural linewidth. Currently, the most accurate optical lattice clocks operate on this narrow transition by tightly trapping strontium-87 atoms in a {\em magic} optical lattice at 813~nm. {\em Magic} wavelengths occur where the Stark shifts of both the ground and excited states are equivalent, thus eliminating any position and intensity-dependent broadening of the corresponding transition. Theoretical calculations of the electronic structure of strontium-87 have also predicted another {\em magic} wavelength of the clock transition at 497.01(57)~nm. In this work, we experimentally measure the novel {\em magic} wavelength to be $497.4363(3)$~nm. Compared to the 813~nm {\em magic} wavelength, 497~nm is closer to the strong 461~nm dipolar transition of strontium, resulting in larger atomic polarizability by an order of magnitude, providing deeper traps with less optical power. The proximity to the 461~transition also leads to an enhanced sensitivity of 334(10)~Hz/(nm\,$E_R$) at the {\em magic} wavelength.

arXiv comment7 pages, 6 figures

References in corpus (29)

• An Optical Lattice Clock with Accuracy and Stability at the $10^{-18}$ Level
• Quantum computing with atomic qubits and Rydberg interactions: Progress and challenges
• Theory and applications of atomic and ionic polarizabilities
• Resolving the gravitational redshift within a millimeter atomic sample
• A Fermi-degenerate three-dimensional optical lattice clock
• An Atom Michelson Interferometer on a Chip Using a Bose-Einstein Condensate
• Magnetic field-induced spectroscopy of forbidden optical transitions with application to lattice-based optical atomic clocks
• A clock with $8\times 10^{-19}$ systematic uncertainty
• Nuclear Spin Effects in Optical Lattice Clocks
• ${}^{87}$Sr lattice clock with inaccuracy below 10${}^{-15}$
• Development of a configuration-interaction + all-order method for atomic calculations
• 2000-times repeated imaging of strontium atoms in clock-magic tweezer arrays
• Blackbody radiation shift in the Sr optical atomic clock
• E1 amplitudes, lifetimes, and polarizabilities of the low-lying levels of atomic ytterbium
• Emergence of multi-body interactions in few-atom sites of a fermionic lattice clock
• Quantum rotation sensing with dual Sagnac interferometers in an atom-optical waveguide
• Fermionic quantum processing with programmable neutral atom arrays
• State-dependent optical lattices for the strontium optical qubit
• Inelastic collisions and density-dependent excitation suppression in a ${}^{87}$Sr optical lattice clock
• Many-body treatment of the collisional frequency shift in fermionic atoms
• Degenerate quantum gases of strontium
• Adiabatic compression of a trapped Fermi gas
• Bragg gravity-gradiometer using the ${}^1$S${}_0$-${}^3$P${}_1$ intercombination transition of ${}^{88}$Sr
• The ${}^1{\mathrm{S}}_0$-${}^3{\mathrm{P}}_2$ magnetic quadrupole transition in neutral strontium
• Atomic interferometer based on optical tweezers
• pCI: a parallel configuration interaction software package for high-precision atomic structure calculations
• Magic wavelengths of the Sr ($5s^2{}^1{S}_0$--$5s5p{}^3{P}_1$) intercombination transition near the $5s5p{}^3{P}_1$--$5p^2{}^3{P}_2$ transition
• Experimental realization of a SU(3) color-orbit coupling in an ultracold gas
• Magic wavelength at 477 nm for the strontium clock transition