With recent developments of topological photonics, the light-matter interaction in a topological quantum optics interface attracts great interest. The topologically protected one-way edge modes in dynamically modulated photonic structures show a way to manipulate the interaction between a single photon and a quantum emitter.

Schematics of a two-level quantum emitter interacting with (a) a topological waveguide from a dynamically modulated photonic system versus (b) a one-dimensional unidirectional waveguide. (c) Spectra of the correlated photon-state in a topological waveguide interacting with an initially excited Λ-type quantum emitter (inset). (d) Left-propagating photon reflection with a frequency upshift and right-propagating photon transmission versus the atom-photon interaction strength of the Λ-type quantum emitter.

We systematically study single-photon quantum optics in a topological waveguide from a dynamically modulated photonic system. We show that light-matter interaction in these one-way edge states can be largely described using a one-dimensional unidirectional waveguide model despite that a photon in a topological waveguide propagates around the resonant site coupled to the quantum emitter due to the topological protection. In addition, using the interaction between a Λ-type three-level quantum emitter and a photon in the topological waveguide, the nonlocal correlated photon-state generation and the single-photon reflection with the frequency conversion are demonstrated. This work provides insight for single-photon quantum optics in topological waveguides and highlights some of the opportunities for the manipulation of the single-photon transport as created from the tunability in dynamically modulated photonic structures, which holds promise for potential applications in quantum-information processing.

The paper has been published in Physical Review Applied with the title “Single-Photon Transport in a Topological Waveguide from a Dynamically Modulated Photonic System”.

Link: https://doi.org/10.1103/PhysRevApplied.14.014063