Coherent evolution of superexchange interaction in seconds long optical clock spectroscopy
Abstract
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
Cite
@article{arxiv.2402.13398,
title = {Coherent evolution of superexchange interaction in seconds long optical clock spectroscopy},
author = {William R. Milner and Stefan Lannig and Mikhail Mamaev and Lingfeng Yan and Anjun Chu and Ben Lewis and Max N. Frankel and Ross B. Hutson and Ana Maria Rey and Jun Ye},
journal= {arXiv preprint arXiv:2402.13398},
year = {2024}
}