@article{13403,
  author = {William Milner and Stefan Lannig and Mikhail Mamaev and Lingfeng Yan and Anjun Chu and Ben Lewis and Max Frankel and Ross Hutson and Ana Maria Rey and Jun Ye},
  title = {Coherent evolution of superexchange interaction in seconds long optical clock spectroscopy},
  abstract = {<p>Measurement science now connects strongly with engineering of quantum coherence, many-body states, and entanglement. To scale up the performance of an atomic clock using a degenerate Fermi gas loaded in a three-dimensional optical lattice, we must understand complex many-body Hamiltonians to ensure meaningful gains for metrological applications. In this work, we use a near unity filled Sr 3D lattice to study the effect of a tunable Fermi-Hubbard Hamiltonian. The clock laser introduces a spin-orbit coupling spiral phase and breaks the isotropy of superexchange interactions, changing the Heisenberg spin model into one exhibiting XXZ-type spin anisotropy. By tuning the lattice confinement and applying imaging spectroscopy we map out favorable atomic coherence regimes. With weak transverse confinement, both s- and p-wave interactions contribute to decoherence and atom loss, and their contributions can be balanced. At deep transverse confinement, we directly observe coherent superexchange interactions, tunable via on-site interaction and site-to-site energy shift, on the clock Ramsey fringe contrast over timescales of multiple seconds. This study provides a groundwork for using a 3D optical lattice clock to probe quantum magnetism and spin entanglement.</p>
},
  year = {2024},
  journal = {Science},
  volume = {in press},
  url = {https://arxiv.org/abs/2402.13398},
}