arXiv subjects

Antoine Borel

Publications and source records attributed to Antoine Borel.

6 recordsLinked to original sources

arXiv2026

Scalable Quantum Interference from Indistinguishable Quantum Dots

Quantum interference of indistinguishable photons is the foundation of photonic quantum technologies, yet scaling from a few to many identical quantum light sources remains a major challenge. In solid-state platforms, spatial and spectral inhomogeneity and resource-intensive architectures impede scaling. As a result, interference between remote, independent quantum emitters has been thus far limited to pairs. Here we introduce a wavefront-shaping approach that enables scalable interference from multiple indistinguishable quantum dots on the same chip. Using programmable spatial light modulators, we independently excite, collect, and route emission from spatially distinct, yet spectrally degenerate dots. Scaling from two to five indistinguishable emitters, we verify interference through cooperative-emission phenomena and Hong-Ou-Mandel two-photon interference, thereby establishing a route towards large-scale, programmable quantum photonic architectures.

quant-ph↗

arXiv2025

High-Temperature Activation of Single-Photon Emitters in monolayer WS2

Controlled activation of defect-bound excitonic states in two-dimensional semiconductors provides a route to isolated quantum emitters and a sensitive probe of defect physics. Here we demonstrate that \textit{in situ} high-temperature annealing of hBN-encapsulated monolayer WS$_2$ on a suspended microheater leads to the emergence of spectrally isolated single-photon emitters at cryogenic temperatures. Annealing at temperatures around 1100 K produces a sharp emission line, $X_L$, red-shifted by approximately 80 meV from the neutral exciton and exhibiting a linewidth below 200 $\mu$eV. Photoluminescence excitation spectroscopy and power-dependent measurements show that $X_L$ originates from annealing-induced defects in the WS$_2$ monolayer, while second-order photon correlation measurements reveal clear antibunching with $g^{(2)}(0)<0.5$. These results establish high-temperature \textit{in situ} annealing as a controlled means to access defect-bound excitonic states and single-photon emission in van der Waals materials.

cond-mat.mtrl-sci↗

arXiv2025

Cavity quantum electrodynamics with single perovskite quantum dots

Quantum emitters of single indistinguishable photons play a key role in quantum technologies. Among condensed matter systems, colloidal perovskite quantum dots have emerged as promising candidates, exhibiting high-purity single photon emission at room temperature and two-photon interference visibilities up to 0.5 at cryogenic temperatures. Achieving deterministic coupling of individual perovskite quantum dots to photonic structures is now a critical step towards harnessing cavity quantum electrodynamics (cQED) effects, such as the Purcell effect, to enhance single photon emission rate and indistinguishability. Here, we demonstrate the deterministic and reversible coupling of individual CsPbBr$_{3}$ perovskite quantum dots to a tunable, high-quality factor, low mode volume fiber-based Fabry-P\'erot microcavity at 10~\si{\kelvin}. By spatially and spectrally tuning the cavity mode in resonance with the quantum dot emission, we observe up to a twofold increase in single photon emission rates. We build on the original multiplet excitonic fine structure to assess the vacuum Rabi coupling strength ($g \simeq$ 40~\si{\micro eV}) from the shaping of the spectral profile of the emission upon increasing the electromagnetic confinement. This approach also made it possible to delineate the contributions of spectral diffusion and pure dephasing to the total linewidth of emission, paving the way to a fully optimized control of the emission properties of cavity coupled perovskite quantum dots.

quant-ph↗

arXiv2024

Luminescence properties of closely packed organic color centers grafted on a carbon nanotube

We report on the photo-luminescence of pairs of organic color centers in single-wall carbon nanotubes grafted with 3,5 dichlorobenzene. Using various techniques such as intensity correlations, super-localization microscopy or luminescence excitation spectroscopy, we distinguish two pairs of color centers grafted on the same nanotube; the distance between the pairs is on the order of several hundreds of nanometers. In contrast, by studying the strong temporal correlations in the spectral diffusion in the framework of photo-induced Stark effect, we can estimate the distance within each pair to be of the order of a few nanometers. Finally, the electronic population dynamics is investigated using time-resolved luminescence and saturation measurements, showing a biexponential decay with a fast overall recombination (compatible with a fast population transfer between the color centers within a pair) and a weak delayed repopulation of the traps possibly due to the diffusion of excitons along the tube axis.

cond-mat.mes-hall↗

arXiv2023

A telecom band single-photon source using a grafted carbon nanotube coupled to a fiber Fabry-Perot cavity in the Purcell regime

We report on the coupling of a reconfigurable high Q fiber micro-cavity to an organic color center grafted to a carbon nanotube for telecom wavelength emission of single photons in the Purcell regime. Using three complementary approaches we assess various figures of merit of this tunable single photon source and of the cavity quantum electrodynamical effects : the brightening of the emitter is obtained by comparison of the count rates of the very same emitter in free-space and cavity coupled regimes. We demonstrate a fiber coupled single-photon output rate up to 20 MHz at 1275~nm. Using time-resolved and saturation measurements, we determine independently the radiative quantum yield and the Purcell factor of the system with values up to 30 for the smallest mode volumes. Finally, we take advantage of the tuning capability of the cavity to measure the spectral profile of the brightness of the source which gives access to the vacuum Rabi splitting $g$ with values up to $25 \; μ$eV.

quant-ph↗

arXiv2019

Super-localization of excitons in carbon nanotubes at cryogenic temperature

At cryogenic temperature and at the single emitter level, the optical properties of single-wall carbon nanotubes depart drastically from that of a one-dimensional (1D) object. In fact, the (usually unintentional) localization of excitons in local potential wells leads to nearly 0D behaviors such as photon antibunching, spectral diffusion, inhomogeneous broadening, etc. Here, we present an hyperspectral imaging of this exciton self-localization effect at the single nanotube level using a super-resolved optical microscopy approach. We report on the statistical distribution of the traps localization, depth and width. We use a quasi-resonant photoluminescence excitation approach to probe the confined quantum states. Numerical simulations of the quantum states and exciton diffusion show that the excitonic states are deeply modified by the interface disorder inducing a remarkable discretization of the excitonic absorption spectrum and a quenching of the free 1D exciton absorption.

cond-mat.mes-hall↗