Controlled directionality of photon emission without nonreciprocal components

Area of Science:

• Quantum optics
• Quantum information science

Background:

• Directional routing of single photons is essential for quantum information processing.
• Existing methods often rely on complex components like circulators or unidirectional waveguides.

Purpose of the Study:

• To propose a new scheme for directional single-photon routing.
• To achieve full directional emission using waveguide quantum dynamics and tunable atom-waveguide couplings.

Main Methods:

• Modeling a system of two 2-level atoms coupled to a 1D waveguide.
• Dynamically tuning atom-waveguide coupling strengths to control emission directionality.
• Introducing direct inter-atom coupling to overcome emission blockage.

Main Results:

• A mechanism where one atom acts as a reflector, enforcing directional emission.
• Overcoming the reflector atom's emission blockage through direct inter-atom coupling.
• Achieving full directional emission of single photons by optimizing coupling functions.

Conclusions:

• The proposed scheme offers a promising solution for directional microwave photon routing.
• This method provides essential support for developing large-scale quantum information processing networks.