Single photon emitter deterministically coupled to a topological corner state

Incorporating topological physics into the realm of quantum photonics holds the promise of developing quantum light emitters with inherent topological robustness and immunity to backscattering.Nonetheless,the deterministic interaction of quantum emitters with topologically nontrivial resonances remains largely unexplored.Here we present a single photon emitter that utilizes a single semiconductor quantum dot,deterministically coupled to a second-order topological corner state in a photonic crystal cavity.By investigating the Purcell enhancement of both single photon count and emission rate within this topological cavity,we achieve an experimental Purcell factor of Fp=3.7.Furthermore,we demonstrate the on-demand emission of polarized single photons,with a second-order autocorrelation function g(2)(0)as low as 0.024±0.103.Our approach facilitates the customization of light-matter interactions in topologically nontrivial environments,thereby offering promising applications in the field of quantum photonics.

Tunable quantum dots in monolithic Fabry-Perot microcavities for high-performance single-photon sources

Cavity-enhanced single quantum dots(QDs)are the main approach towards ultra-high-performance solid-state quantum light sources for scalable photonic quantum technologies.Nevertheless,harnessing the Purcell effect requires precise spectral and spatial alignment of the QDs’emission with the cavity mode,which is challenging for most cavities.Here we have successfully integrated miniaturized Fabry-Perot microcavities with a piezoelectric actuator,and demonstrated a bright single-photon source derived from a deterministically coupled QD within this microcavity.Leveraging the cavity-membrane structures,we have achieved large spectral tunability via strain tuning.On resonance,a high Purcell factor of~9 is attained.The source delivers single photons with simultaneous high extraction efficiency of 0.58,high purity of 0.956(2)and high indistinguishability of 0.922(4).Together with its compact footprint,our scheme facilitates the scalable integration of indistinguishable quantum light sources on-chip,therefore removing a major barrier to the development of solid-state quantum information platforms based on QDs.

Filter-free high-performance single-photon emission from a quantum dot in a Fabry–Perot microcavity

Combining resonant excitation with Purcell-enhanced single quantum dots(QDs)stands out as a prominent strategy for realizing high-performance solid-state single-photon sources.However,optimizing photon extraction efficiency requires addressing the challenge of effectively separating the excitation laser from the QDs’emission.Traditionally,this involves polarization filtering,limiting the achievable polarization directions and the scalability of polarized photonic states.In this study,we have successfully tackled this challenge by employing spatially orthogonal resonant excitation of QDs,deterministically coupled to monolithic Fabry–Perot microcavities.Leveraging the planar microcavity structure,we have achieved spectral filter-free single-photon resonant fluorescence.The resulting source produces single photons with a high extraction efficiency of 0.87 and an indistinguishability of 0.963(4).