Deterministic single photon subtraction with a cascade of waveguide-coupled atoms

Area of Science:

• Quantum Optics
• Quantum Information Science

Background:

• Deterministic single-photon sources are crucial for quantum technologies.
• Existing methods for photon subtraction face limitations in efficiency and state preservation.

Purpose of the Study:

• To develop a specialized photon subtraction scheme for deterministic single-photon extraction.
• To enhance the security of quantum key distribution (QKD) against photon number splitting attacks.

Main Methods:

• Integration of two Λ-type emitters coupled to a chiral waveguide via single photon Raman interaction (SPRINT).
• Development of a theoretical model using input-output formalism within the SLH framework.
• Numerical simulations of the system's interaction with few-photon pulses.

Main Results:

• The proposed scheme enables deterministic extraction of single photons from multiphoton states.
• Input single-photon states are preserved unaltered during the subtraction process.
• The two-emitter extension of SPRINT improves upon the original scheme for QKD security.

Conclusions:

• The developed scheme offers a robust method for generating high-quality single photons.
• This advancement significantly strengthens the security of quantum key distribution protocols.
• The SPRINT-based approach provides a promising avenue for future quantum communication systems.