Universal pair polaritons in a strongly interacting Fermi gas

Area of Science:

• Quantum optics
• Atomic physics
• Condensed matter physics

Background:

• Cavity quantum electrodynamics (QED) typically studies one-body light-matter interactions.
• Quantum simulation of many-body systems using QED has relied on multi-photon processes.
• Existing methods scale down light-matter interactions, limiting direct observation of many-body phenomena.

Purpose of the Study:

• To investigate novel light-matter coupling mechanisms in many-body systems.
• To explore the use of molecular transitions in Fermi gases for cavity QED experiments.
• To enable direct observation and manipulation of quantum correlations in strongly interacting systems.

Main Methods:

• Experiments utilizing cavity QED with molecular transitions in a strongly interacting Fermi gas.
• Directly coupling cavity photons to pairs of atoms.
• Observing and analyzing the properties of resulting pair polaritons.

Main Results:

• Successfully created and resolved pair polaritons, which are hybrid excitations of photons, atom pairs, and molecules.
• Demonstrated a universal dependence of the pair-polariton spectrum on interatomic interactions.
• Showcased a direct mapping between ground-state pair correlations and the optical spectrum, magnifying many-body effects by two orders of magnitude.

Conclusions:

• This work establishes a new paradigm for cavity QED, moving beyond one-body processes to directly address many-body correlations.
• The developed system enables fast, minimally destructive measurements of pair correlations.
• Opens pathways for quantum-limited measurements and coherent manipulation of these correlations using quantized optical fields.