Collective atom-cavity coupling and non-linear dynamics with atoms with multilevel ground states

• Main Authors: Suarez, Elmer, Carollo, Federico, Lesanovsky, Igor, Olmos, Beatriz, Courteille, Philippe W, Slama, Sebastian
• Format: Journal Article
• Language: English
• Published: 12-10-2022
• Subjects: Physics - Atomic Physics; Physics - Quantum Physics
• DOI: 10.48550/arxiv.2210.06085

We investigate experimentally and theoretically the collective coupling
between atoms with multilevel ground state manifolds and an optical cavity
mode. In our setup the cavity field optically pumps populations among the
ground states. The ensuing dynamics can be conveniently described by means of
an effective dynamical atom-cavity coupling strength that depends on the
occupation of the individual states and their coupling strengths with the
cavity mode. This leads to a dynamical backaction of the atomic populations on
the atom-cavity coupling strength which results in a non-exponential relaxation
dynamics. We experimentally observe this effect with laser-cooled $^{87}$Rb
atoms, for which we monitor the collective normal-mode splitting in real time.
Our results show that the multilevel structure of electronic ground states can
significantly alter the relaxation behavior in atom-cavity settings as compared
to ensembles of two-level atoms.