Deterministic Arrays of Single-Photon Sources

Woong Bae Jeon, Dong Hyun Park, Jong Sung Moon +3 more

Scalable, reliable single-photon sources are essential for quantum photonic technologies. In particular, a fiber-based platform is desirable form for practical single-photon devices. Although recent advances with solid-state quantum emitters on fiber platforms have enabled the generation of single photons with high-performance, the reliable, scalable implementation of multiple sources on the compact fiber platform remains challenging. Here, we present a multiple, tunable array of quantum photonic devices in the fiber-based platform. We developed the selective integration for multiple quantum dot devices, and implemented multi-channel single-photon device based on a V-groove fiber platform. The device offers scalability, tunability, high fabrication yield, and high single-photon coupling efficiency. Therefore, this fiber-integrated quantum platform provides a scalable and reliable multichannel single-photon source.

Herbert, Walther

Andreas Christ, Christine Silberhorn

Parametric down-conversion (PDC) is one of the most widely used methods to create pure single-photon states for quantum information applications. However, little attention has been paid to higher-order photon components in the PDC process, yet these ultimately limit the prospects of generating single photons of high quality. In this paper we investigate the impact of higher-order photon components and multiple frequency modes on the heralding rates and single-photon fidelities. This enables us to determine the limits of PDC sources for single-photon generation. Our results show that a perfectly single-mode PDC source in conjunction with a photon-number-resolving detector is ultimately capable of creating single-photon Fock states with unit fidelity and a maximal state creation probability of 25$%$. Hence, an array of 17 switched sources is required to build a deterministic ($>$99$%$ emission probability) pure single-photon source.

Jiefei Zhang, Swarnabha Chattaraj, Qi Huang +3 more

The first two decades of the 21st century have witnessed remarkable progress in harnessing the power of quantum mechanics, on-chip, enabled by the development in epitaxial semiconductor nanoscience with proof-of-principle demonstrations -- many tour-de force -- of quantum functionalities such as entanglement and teleportation amongst photon and matter qubits ---quintessential quantum phenomena that underpin the development of quantum technologies. A basic hindrance to such development however has been the absence of a platform of on-demand single photon sources (SPSs) with adequate spectral characteristics and arranged in spatially regular arrays necessary for their incorporation in surrounding light manipulation units to enable quantum networks. Here we report on the first spatially-ordered, scalable platform of deterministic, bright, spectrally highly uniform, pure, and indistinguishable SPSs. At 19.5K, and without Purcell enhancement, these SPSs exhibit emission purity ~99.2% and two-photon interference (TPI) indistinguishability ~57%. Oscillation behavior of the photon emission indicates that the photons originate from a coherent superposition of two excitonic states, revealing effectively a three-level electronic structure which can be exploited as potential two-frequency qubit generating energy entangled photons for teleportation. Time-dependent two photon interference (Hong-Ou Mandel interferometry) coincidence counts g(2)({\tau}) near {\tau}=0 show effectively zero count which, analyzed using the three-level model, reveals a highly encouraging dephasing time of ~0.58ns at ~20K. Such SPS arrays in a planarized structure open the pathway to creating interconnected quantum networks for application in communication, sensing, computing and more.

Daniel Istrate