Single photon sources play a fundamental role in quantum science and engineering. In the first part of the talk a will present a deterministic quantum light source in silicon based on single emissive centers that emit in the telecom band [1]. In the second part of the talk, I will discuss a probabilistic source based on an interpretable inverse design cavity enhancing the efficiency of on-chip photon pair generation rate through nonlinear processes [2]. I will also discuss how topological disorder can enhance non-linearities on chip [3].
Single photon sources play a fundamental role in quantum science and engineering. In the first part of the talk a will present a deterministic quantum light source in silicon based on single emissive centers that emit in the telecom band [1]. In the second part of the talk, I will discuss a probabilistic source based on an interpretable inverse design cavity enhancing the efficiency of on-chip photon pair generation rate through nonlinear processes [2]. I will also discuss how topological disorder can enhance non-linearities on chip [3].
Single photon sources play a fundamental role in quantum science and engineering. In the first part of the talk, I will present a deterministic quantum light source in silicon based on single emissive centers that emit in the telecom band [1]. In the second part of the talk, I will discuss a probabilistic source based on an interpretable inverse design cavity enhancing the efficiency of on-chip photon pair generation rate through nonlinear processes [2]. I will also discuss how topological disorder can enhance non-linearities on chip [3]. References. 1- W. Redjem*, Y. Zhiyenbayev*, W. Qarony* et al., “All-silicon quantum light source by embedding an atomic emissive center in a nanophotonic cavity,” Nat Commun 14, 3321 (2023). 2- Z. Jia, W. Qarony, J. Park, S. Hooten, D. Wen, Y. Zhiyenbayev, M. Seclì, W. Redjem, S. Dhuey, A. Schwartzberg, E. Yablonovitch, and B. Kanté, “Interpretable inverse-designed cavity for on-chip nonlinear photon pair generation,” Optica 10, 1529-1534 (2023). 3- Z. Jia, M. Seclì, A. Avdoshkin et al., “Disordered topological graphs enhancing nonlinear phenomena,” Sci. Adv. 9, 14 (2023).
The capability of realizing quantum photonics implementations on-chip will have a strong impact on several aspects of quantum computation and information processing. The implementation of large scale integrated quantum photonic technologies requires on-chip reconfigurable waveguide circuits as well as single-photon sources and detectors. Many successes have been made in recent years to demonstrate complex quantum circuits in many material platforms. Among all these platforms, the Silicon-on-Insulator (SOI) platform is outstanding as it is well developed for classical applications and therefore deploys a high component density, mature fabrication techniques and compatibility with the telecom regime and the complementary metal-oxide-semiconductor (CMOS) technology. However, the lack of on-demand non-classical light sources, directly incorporated in silicon chips, forces the use of nonlinear processes to generate non-classical light states: the probabilistic nature of the emission process sets a limit in the maximally achievable experimental complexity. The use of on-demand sources will have a strong impact on the device’s scalability.
Chip-scale integrated photonic circuits provide an attractive platform for the implementation of many quantum photonic technologies ranging from precise metrology to secure communication and quantum computation. In particular, silicon photonic platforms support micron-scale nonlinear optical sources of non-classical light which can be mass manufactured using the robust fabrication processes pioneered by the CMOS microelectronics industry. Integration of these quantum photonic sources with high-performance classical photonic devices on the same chip is required for truly scalable quantum information technologies. Integrated nonlinear resonators are investigated as sources of quantum mechanically correlated photon pair sources. An all-order dispersion engineering method is presented as a robust design synthesis for micoring sources. In addition, a novel concept of coupled mode dispersion compensation is proposed and demonstrated, providing significantly improved performance characteristics of resonant four-wave mixing sources. Next a photon pair source is demonstrated in a commercial CMOS microelectronics process opening the door to future integration of quantum photonics with electronic logic and control circuits. Classical nonlinear optical measurements of stimulated four-wave mixing are used for the first time to accurately predict the quantum correlations from the same device operating in the photon pair regime. Next the first demonstration of fully on-chip pump rejection is demonstrated with over 95 dB pump extinction improving the figures of merit from previous demonstrations by multiple orders of magnitude, including losses, detected pair rates and size. Finally, proposals for introducing novel degrees of freedom provided by an integrated platform are presented for further improving the performance of both photon pair and classical nonlinear optical sources.
Photons are excellent carriers of quantum information. The generation, manipulation and read-out of photonic quantum states have enabled pioneering investigations in quantum physics, paving the way to groundbreaking technologies. Integrated quantum photonics, that is the processing of photons on-chip, is at the forefront of this revolution. In particular, silicon integrated circuits have emerged as the dominant material platform for large-scale quantum photonics. However, the difficulty to inject single photons on-demand in a silicon chip is a major obstacle to the level of complexity of current systems. In this context, the isolation of individual fluorescent defects in silicon, called color centers, opens an avenue toward the integration of atomic sources of single photons. While several color centers have demonstrated an ability to generate antibunched photons, practical applications require tailoring of their emission through quantum electrodynamics effects in optical cavities.This PhD thesis is devoted to cavity quantum electrodynamics with color centers in silicon optical cavities, in view of building an efficient source of single photons. The efforts are first focused on ensembles of G centers in microring cavities. The optical properties of cavity-coupled G centers are studied using microphotoluminescence spectroscopy, and an enhancement of their zero-phonon emission rate by Purcell effect is demonstrated. However, a quantitative analysis reveals a poor quantum efficiency, motivating the choice of another emitter for further experiments. Subsequently, the efforts are focused on the W center. Purcell enhancement of the overall recombination rate is observed for an ensemble of W centers in a circular Bragg grating cavity. Using a quantitative analysis based on finite-difference time-domain calculation, a high quantum efficiency is estimated. The results being encouraging for the purpose of single photon emission, an optical setup is developed for single-emitter spectroscopy and a strategy is devised to fabricate individually-adressable emitters, leading to the isolation of single W centers in unpatterned silicon-on-insulator. Using a nanofabrication process allowing for deterministic positionning, the emitters are embedded into circular Bragg grating cavities, resulting in an increase of the photoluminescence intensity by orders of magnitude by Purcell effect. This work leads to the demonstration of a source of triggered single photons.A next milestone will be the demonstration of a single photon source for integrated photonic circuits, based on a color center in a waveguide-coupled optical cavity. Beyond the interest for integrated quantum photonics, the observation of bright photoluminescence from single color centers opens perspectives for further experiments, allowing to probe fundamental questions relative to their photophysics.
Silicon is the ideal material for building electronic and photonic circuits at scale. Integrated photonic quantum technologies in silicon offer a promising path to scaling by leveraging advanced semiconductor manufacturing and integration capabilities. However, the lack of deterministic quantum light sources and strong photon-photon interactions in silicon poses a challenge to scalability. In this work, we demonstrate an indistinguishable photon source in silicon photonics based on an artificial atom. We show that a G center in a silicon waveguide can generate high-purity telecom-band single photons. We perform high-resolution spectroscopy and time-delayed two-photon interference to demonstrate the indistinguishability of single photons emitted from a G center in a silicon waveguide. Our results show that artificial atoms in silicon photonics can source single photons suitable for photonic quantum networks and processors.
We propose an efficient, scalable, and deterministic scheme to generate multiple indistinguishable photons over independent channels, on demand. Our design relies on multiple single-photon sources, each coupled to a waveguide, all interacting with a common cavity mode. The cavity synchronizes and triggers the simultaneous emission of one photon by each source, which are collected by the waveguides. In a state-of-the-art circuit QED implementation, this scheme supports the creation of single photons with 99 % purity, indistinguishability, and efficiency at rates of ∼ MHz . We also discuss conditions to produce up to 100 photons simultaneously with generation rates of hundreds of kHz. This is orders of magnitude more efficient than previous demultiplexed sources for boson sampling and enables the realization of deterministic multiphoton sources and scalable quantum information processing with photons. Published by the American Physical Society 2024