Control of photon-photon interaction via a cavity

Area of Science:

• Quantum optics
• Quantum information processing
• Atomic physics

Background:

• Controlling photon-photon interactions is crucial for quantum information processing.
• Few-photon level interactions are key for developing quantum technologies.

Purpose of the Study:

• Investigate two-photon interactions via a Ξ-type atom coupled to a waveguide and cavity.
• Analyze the influence of cavity initial state on quantum emitter configuration and photon behavior.

Main Methods:

• Theoretical investigation of a Ξ-type atom interacting with a one-dimensional waveguide and a cavity field.
• Analysis of photon transmission and bound states under different cavity conditions (vacuum vs. Fock state).
• Derivation of exact out-state functions for plane wave inputs to study photon bunching and antibunching.

Main Results:

• The cavity's initial state dictates the quantum emitter's effective configuration.
• A single bound state exists in a vacuum cavity; two bound states emerge in a Fock state cavity (n≠0).
• Photon transmission exhibits oscillations in spatial separation due to multiple bound states, leading to controllable bunching and antibunching behaviors.

Conclusions:

• The cavity state significantly modifies the quantum emitter's properties and photon interaction dynamics.
• Tunable spatial attraction/repulsion between transmitted photons is achievable by controlling cavity parameters.
• This study provides insights into controlling quantum interactions for advanced quantum information processing.