Description
The search for passive, deterministic conditional gates between photons remains a major objective within the quantum optics and Waveguide QED community. Many proposals have emerged using different quantum non-linear media such as Rydberg atoms, Kerr non-linearities or V-type emitters. We wanted to answer the question: can the simplest form of quantum non-linearity—a two-level emitter—be harnessed to construct a photonic conditional gate? The use of two-level emitters has posed challenges, as strong photon correlations usually come at the price of significant distortions in the wavepacket spectrum. I will present our approach to overcome these limitations through a novel architecture [1]. This design can be realized within a two-mode chiral Waveguide QED framework, such as the one resulting from a two-level emitter coupled to a topological waveguide. I will finally talk about a recent proposal for an equivalent two-photon gate designed for supercoducting circuits.
References
[1] T. Levy-Yeyati, C. Vega, T. Ramos and A. Gonzalez-Tudela, PRX Quantum 6, 010342
(2025)
