Resonance Fluorescence from Waveguide-Coupled Strain-Localized Two-Dimensional Quantum Emitters

Efficient on-chip integration of single-photon emitters imposes a major bottleneck for applications of photonic integrated circuits in quantum technologies. Resonantly excited solid-state emitters are emerging as near-optimal quantum light sources, if not for the lack of scalability of current devices.<br/>A promising scalable platform is based on two-dimensional (2D) semiconductors. However, resonant excitation and single-photon emission of waveguide-coupled 2D emitters have proven to be elusive. Here, we show a scalable approach using a silicon nitride photonic waveguide to simultaneously strain-localize single-photon emitters from a tungsten diselenide (WSe₂) monolayer [1,2] and to couple them into a waveguide mode [3]. We demonstrate the guiding of single photons in the photonic circuit by measuring second-order autocorrelation of g⁽²⁾(0)=0.150±0.093 and perform on-chip resonant excitation yielding a g⁽²⁾(0)=0.377±0.081 [4]. These results open up the way towards coherent control of 2D quantum emitters and more elaborate two-dimensional emitter based on-chip quantum photonic circuits.<br/><br/>[1] A. Branny, et al., Nat. Commun., 8, 15053, (2017).<br/>[2] C. Palacios-Berraquero, et al., Nat. Commun. 8, 15093, (2017).<br/>[3] F. Peyskens, et al., Nat. Commun., 10, 4435, (2019).<br/>[4] C. Errando-Herranz, et al., ACS Photonics, 8, 4, 1069–1076 (2021).