Progress in exploring infinite-range many-body physics in a strontium cavity-QED platform

When atoms with a narrow-linewidth transition are collectively coupled to a detuned optical cavity, they exhibit an effective spin-spin interaction which has infinite range [1]. Previously, we demonstrated that competition between these spin-exchange dynamics and an external drive along the ¹S₀-³P₁ transition in ⁸⁸Sr leads to a dynamical phase transition [2].  Current efforts are focused on extending this physics to a multilevel system by allowing atoms to populate different Zeeman sublevels of the excited state. Through a combination of QND-style probing through the cavity and heterodyne measurements of the atoms’ self-radiated field, we expect to observe three distinct dynamical phases in analogy to phases in a BCS superconductor [3].

[1] Norcia et al., Science 361, 259-262 (2018)

[2] Muniz et al., Nature 580, 602-607 (2020)

[3] Lewis-Swan et al., arXiv:2011.13007v1 (2020)