Observation of strong coupling between one atom and a monolithic microresonator

Area of Science:

• Quantum Optics
• Quantum Information Science
• Cavity Quantum Electrodynamics

Background:

• Strong light-matter interactions at the single-photon level are crucial for quantum optics and information science.
• Cavity quantum electrodynamics experiments have primarily used Fabry-Perot resonators with single atoms.
• Challenges in improving Fabry-Perot resonators and scaling devices drive the search for alternative microcavity systems.

Purpose of the Study:

• To demonstrate strong coupling between individual caesium atoms and a toroidal microresonator.
• To investigate optical processes with single atoms and photons in microcavity systems.
• To explore applications in quantum networks and quantum information processing.

Main Methods:

• Utilized a high-quality toroidal microresonator.
• Observed transit events of single caesium atoms falling through the resonator's evanescent field.
• Developed a theoretical model to quantify coupling rates.

Main Results:

• Achieved strong coupling between individual caesium atoms and toroidal microresonator fields.
• Determined the coherent coupling rate for atom-resonator interactions.
• Demonstrated that coherent coupling rates exceed dissipative rates of the atom and cavity.

Conclusions:

• Strong coupling in toroidal microresonators is feasible with individual atoms.
• This work paves the way for using lithographically fabricated microresonators in quantum technologies.
• Potential applications include quantum networks, scalable quantum logic, and atom chip-based quantum information processing.