Single ion coupled to an optical fiber cavity

Area of Science:

• Quantum physics
• Atomic physics
• Optical physics

Background:

• Trapped ions are promising qubits for quantum computing.
• Optical cavities enhance light-matter interactions.
• Integrating ions and cavities is challenging but crucial for quantum technologies.

Purpose of the Study:

• To realize and characterize a hybrid system of a single trapped ion and a compact optical fiber cavity.
• To investigate the spatial coupling between the ion and the cavity.
• To measure the ion-cavity coupling strength and assess its potential for quantum applications.

Main Methods:

• Confining a single Ytterbium ion (Yb(+)) within a micron-scale ion trap.
• Integrating the ion trap inside a 230 μm-long optical fiber cavity.
• Characterizing spatial ion-cavity coupling.
• Measuring ion-cavity coupling strength via a cavity-stimulated Lambda (Λ) transition.

Main Results:

• Demonstrated successful integration of a single Yb(+) ion with an optical fiber cavity.
• Characterized the spatial ion-cavity coupling, confirming efficient interaction.
• Measured ion-cavity coupling strength exceeding the natural decay rate due to the small mode volume.
• Achieved strong coherent coupling between the ion and a single photon.

Conclusions:

• The developed system exhibits strong ion-photon coupling, a key requirement for quantum networks.
• This work represents a significant step towards cavity quantum electrodynamics (cQED) for trapped-ion quantum information processing.
• The compact and integrated nature of the system is suitable for scalable ion-photon quantum networks.