Strong atom-field coupling for Bose-Einstein condensates in an optical cavity on a chip

Area of Science:

• Quantum Optics
• Atomic Physics
• Cavity Quantum Electrodynamics

Background:

• The strong coupling regime in cavity quantum electrodynamics enhances atom-photon interactions.
• Achieving strong coupling with single atoms is well-established, but extending this to many-atom systems like Bose-Einstein Condensates (BECs) has been challenging.
• Previous experiments have combined BECs and optical cavities, but not in the strong-coupling regime for individual atoms.

Purpose of the Study:

• To experimentally realize strong coupling between BECs and optical cavities.
• To develop a system enabling deterministic positioning and control of BECs within an optical cavity.
• To investigate the behavior and properties of strongly coupled BEC-cavity systems.

Main Methods:

• Utilized a fiber-based optical cavity combined with atom-chip technology.
• Implemented deterministic positioning of BECs within the cavity, localized at a single antinode.
• Studied the system's response through cavity transmission measurements and spectral mapping.

Main Results:

• Achieved identical strong coupling for many atoms within the cavity mode.
• Demonstrated controlled and tunable coupling rates by positioning the BEC.
• Observed vacuum Rabi splittings exceeding 20 GHz and an additional splitting attributed to atomic hyperfine structure.
• Found no measurable heating in strongly coupled BECs during cavity transmission measurements.

Conclusions:

• The developed system successfully integrates BECs with optical cavities in the strong-coupling regime.
• This platform offers precise control over light-matter interactions for BECs.
• The system shows promise as a robust light-matter quantum interface for quantum information processing.