Enhanced quantum interface with collective ion-cavity coupling

Area of Science:

• Quantum optics
• Atomic physics
• Quantum information science

Background:

• Entangled states of ions are crucial for quantum information processing.
• Controlling light-matter interactions in optical cavities is key for efficient quantum information transfer.

Purpose of the Study:

• To prepare and control a two-ion entangled state coupled to an optical cavity.
• To investigate the transition from subradiance to superradiance by tuning the entangled state phase.
• To demonstrate enhanced quantum information transfer using a superradiant two-ion state.

Main Methods:

• Preparation of a maximally entangled state of two ions.
• Coupling both ions to the mode of an optical cavity.
• Tuning the phase of the entangled state to control collective ion-cavity interaction.
• Encoding a single qubit in the two-ion superradiant state.

Main Results:

• Demonstrated control over collective ion-cavity interaction, enabling a transition from subradiance to superradiance.
• Showcased suppression and enhancement of single photon emission into the cavity.
• Achieved enhanced transfer of quantum information onto a photon using the superradiant state.

Conclusions:

• The phase of an entangled ion state dictates collective interaction with an optical cavity.
• Superradiance in a two-ion system significantly enhances quantum information transfer to a photon.
• This work provides a pathway for improved quantum communication protocols.