papers

Publications (41)

cond-mat.mtrl-sci2023

Excitation's lifetime extracted from electron-photon (EELS-CL) nanosecond-scale temporal coincidences

Nadezda Varkentina, Yves Auad, Steffi Y. Woo +9

Electron-photon temporal correlations in electron energy loss (EELS) and cathodoluminescence (CL) spectroscopies have recently been used to measure the relative quantum efficiency…

cond-mat.mes-hall2022

eV electron spectromicroscopy using free-space light

Yves Auad, Eduardo J. C. Dias, Marcel Tencé +7

The synergy between free electrons and light has recently been leveraged to reach an impressive degree of simultaneous spatial and spectral resolution, enabling applications in mic…

cond-mat.mtrl-sci2024

Quantum Confined Luminescence in Two dimensions

Saiphaneendra Bachu, Fatimah Habis, Benjamin Huet +13

Achieving localized light emission from monolayer two-dimensional (2D) transition metal dichalcogenides (TMDs) embedded in the matrix of another TMD has been theoretically proposed…

physics.ins-det2020

Three dimensional vectorial imaging of surface phonons

Xiaoyan Li, Georg Haberfehlner, Ulrich Hohenester +3

While phonons and their related properties have been studied comprehensively in bulk materials, a thorough understanding of surface phonons for nanoscale objects remains elusive. I…

physics.optics2023

High efficiency coupling of free electrons to sub- modal volume, high-Q photonic cavities

Malo Bézard, Imène Si Hadj Mohand, Luigi Ruggierio +6

We report on the design, realization and experimental investigation by spatially resolved monochromated electron energy loss spectroscopy (EELS) of high quality factor cavities wit…

cond-mat.mtrl-sci2020

Can Copper Nanostructures Sustain High-Quality Plasmons?

Vahagn Mkhitaryan, Katia March, Eric Tseng +10

Silver is considered to be the king among plasmonic materials because it features low inelastic absorption in the visible and infrared (vis-IR) spectral regions compared to other m…

physics.optics2019

Electron Beam Spectroscopy for Nanophotonics

Albert Polman, Mathieu Kociak, F. Javier García de Abajo

Progress in electron-beam spectroscopies has recently enabled the study of optical excitations with combined space, energy and time resolution in the nanometer, millielectronvolt a…

quant-ph2019

Probing Quantum Optical Excitations with Fast Electrons

Valerio Di Giulio, Mathieu Kociak, F. Javier García de Abajo

Probing optical excitations with nanometer resolution is important for understanding their dynamics and interactions down to the atomic scale. Electron microscopes currently offer…

cond-mat.mes-hall2020

Bridging nano-optics and condensed matter formalisms in a unified description of inelastic scattering of relativistic electron beams

Hugo Lourenço-Martins, Axel Lubk, Mathieu Kociak

In the last decades, the blossoming of experimental breakthroughs in the domain of electron energy loss spectroscopy (EELS) has triggered a variety of theoretical developments. Tho…

cond-mat.mes-hall2022

Cathodoluminescence excitation spectroscopy: nanoscale imaging of excitation pathways

Nadezda Varkentina, Yves Auad, Steffi Y. Woo +9

Following the lifespan of optical excitations from their creation to decay into photons is crucial in understanding materials optical properties. Macroscopically, techniques such a…

cond-mat.mtrl-sci2025

Cathodoluminescence, light injection and EELS in STEM: From comparative to coincidence experiments

Luiz H. G. Tizei, Yves Auad, Florian Castioni +1

Electron spectroscopy implemented in electron microscopes provides high spatial resolution, down to the atomic scale, of the chemical, electronic, vibrational and optical propertie…

cond-mat.mes-hall2025

Optical absorption in hexagonal-diamond Si and Ge nanowires: insights from STEM-EELS experiments and ab initio theory

Luiz H. G. Tizei, Michele Re Fiorentin, Thomas Dursap +6

Hexagonal-diamond (2H) group IV nanowires are key for advancing group IV-based lasers, quantum electronics, and photonics. Understanding their dielectric response is crucial for pe…

cond-mat.mtrl-sci2012

Nanometer Scale Spectral Imaging of Quantum Emitters in Nanowires and Its Correlation to Their Atomically Resolved Structure

Luiz Fernando Zagonel, Stefano Mazzucco, Marcel Tencé +9

We report the spectral imaging in the UV to visible range with nanometer scale resolution of closely packed GaN/AlN quantum disks in individual nanowires using an improved custom-m…

physics.ins-det2022

Event-based hyperspectral EELS: towards nanosecond temporal resolution

Yves Auad, Michael Walls, Jean-Denis Blazit +5

The acquisition of a hyperspectral image is nowadays a standard technique used in the scanning transmission electron microscope. It relates the spatial position of the electron pro…

cond-mat.mtrl-sci2024

Nanosecond nanothermometry in an electron microscope

Florian Castioni, Yves Auad, Jean-Denis Blazit +8

Thermal transport in nanostructures plays a critical role in modern technologies. As devices shrink, techniques that can measure thermal properties at nanometer and nanosecond scal…

physics.optics2021

Local Optical Chirality Induced by Near-Field Mode Interference in Achiral Plasmonic Metamolecules

Andreas Horrer, Yinping Zhang, Davy Gérard +4

When circularly polarized light interacts with a nanostructure, the optical response depends on the geometry of the structure. If the nanostructure is chiral (i.e., it cannot be su…

physics.optics2019

Visualizing plasmon-exciton polaritons at the nanoscale using electron microscopy

Andrew B. Yankovich, Battulga Munkhbat, Denis G. Baranov +7

Polaritons are compositional light-matter quasiparticles that have recently enabled remarkable breakthroughs in quantum and nonlinear optics, as well as in material science. Despit…

cond-mat.mtrl-sci2017

Vibrational surface EELS probes confined Fuchs-Kliewer modes

Hugo Lourenço-Martins, Mathieu Kociak

Recently, two reports have demonstrated the amazing possibility to probe vibrational excitations from nanoparticles with a spatial resolution much smaller than the corresponding fr…

physics.app-ph2020

Spectroscopies and electron microscopies unravel the origin of the first colour photographs

Victor de Seauve, Marie-Angélique Languille, Mathieu Kociak +7

The first colours photographs were created by a process introduced by Edmond Becquerel in 1848. The nature of these photochromatic images colours motivated a debate between scienti…

cond-mat.mtrl-sci2014

Excitons and stacking order in h-BN

Romain Bourrellier, Michele Amato, Luiz Henrique Galvão Tizei +8

The strong excitonic emission at 5.75 eV of hexagonal boron nitride (h-BN) makes this material one of the most promising candidate for light emitting devices in the far ultraviolet…

cond-mat.mtrl-sci2025

Single photon emitters in hBN: Limitations of atomic resolution imaging and potential sources of error

David Lamprecht, Shrirang Chokappa, Alissa M. Freilinger +9

There is a growing interest in identifying the origin of single-photon emission in hexagonal boron nitride (hBN), with proposed candidates including boron and nitrogen vacancies as…

physics.optics2019

Point defect states emergence in a plasmonic crystal

Hikaru Saito, Hugo Lourenço-Martins, Noémie Bonnet +6

Plasmonic crystals are well known to have band structure including a bandgap, enabling the control of surface plasmon propagation and confinement. The band dispersion relation of b…

cond-mat.mtrl-sci2014

Atomic Configuration of Nitrogen Doped Single-Walled Carbon Nanotubes

Raul Arenal, Katia March, Chris P. Ewels +4

Having access to the chemical environment at the atomic level of a dopant in a nanostructure is crucial for the understanding of its properties. We have performed atomically-resolv…

physics.optics2022

Unveiling the coupling of single metallic nanoparticles to whispering-gallery microcavities

Yves Auad, Cyrille Hamon, Marcel Tencé +6

Whispering-gallery mode resonators host multiple trapped narrowband circulating optical resonances that find applications in quantum electrodynamics, optomechanics, and sensing. Ho…

cond-mat.mes-hall2023

Engineering 2D material exciton lineshape with graphene/h-BN encapsulation

Steffi Y. Woo, Fuhui Shao, Ashish Arora +20

Control over the optical properties of atomically thin two-dimensional (2D) layers, including those of transition metal dichalcogenides (TMDs), is needed for future optoelectronic…

cond-mat.mes-hall2025

Roadmap for Quantum Nanophotonics with Free Electrons

F. Javier García de Abajo, Albert Polman, Cruz I. Velasco +44

Over the past century, continuous advancements in electron microscopy have enabled the synthesis, control, and characterization of high-quality free-electron beams. These probes ca…

cond-mat.mes-hall2021

Nanoscale modification of WS trion emission by its local electromagnetic environment

Noémie Bonnet, Hae Yeon Lee, Fuhui Shao +9

Structural, electronic, and chemical nanoscale modifications of transition metal dichalcogenide monolayers alter their optical properties, including the generation of single photon…

cond-mat.mtrl-sci2018

Cubic BN optical gap and intragap optically active defects

Anna Tararan, Stefano di Sabatino, Matteo Gatti +6

We report a comprehensive study on the optical properties of cubic boron nitride (c-BN) and its optically active defects. Using electron energy-loss spectroscopy (EELS) within a mo…

physics.optics2025

Plasmon-interband hybridization and anomalous production of hot electrons in aluminum nanoantennas

Jérôme Martin, Oscar Avalos-Ovando, Thomas Simon +9

Strong coupling typically occurs between two separate objects or between an object and its environment (such as an atom and a cavity). However, it can also occur between two differ…

physics.optics2017

Probing the symmetry of the potential of localized surface plasmon resonances with phase-shaped electron beams

Giulio Guzzinati, Armand Béché, Hugo Lourenço--Martins +3

Plasmonics, the science and technology of the interaction of light with metallic objects, is fundamentally changing the way we can detect, generate and manipulate light. Although t…

physics.optics2020

Optical polarization analogue in free electrons beams

Hugo Lourenço-Martins, Davy Gérard, Mathieu Kociak

Fast electrons spectromicroscopies enable to measure quantitatively the optical response of excitations with unrivaled spatial resolution. However, due to their inherently scalar n…

physics.ins-det2025

Advancing Time-Resolved Spectroscopies with Custom Scanning Units and Event-Based Electron Detection

Yves Auad, Florian Castioni, Jassem Baaboura +9

Direct electron detection is revolutionizing electron microscopy by offering lower noise, reduced point-spread function, and increased quantum efficiency. Among these advancements,…

physics.optics2022

Tomographic reconstruction of quasistatic surface polariton fields

Raphael Hauer, Georg Haberfehlner, Gerald Kothleitner +2

We theoretically investigate the tomographic reconstruction of the three-dimensional photonic environment of nanoparticles. As input for our reconstruction we use electron energy l…

physics.optics2022

Aluminum Cayley trees as scalable, broadband, multi-resonant optical antennas

Thomas Simon, Xiaoyan Li, Jérôme Martin +4

An optical antenna can convert a propagative optical radiation into a localized excitation, and reciprocally. Although optical antennas can be readily created using resonant nanopa…

physics.ins-det2023

Time calibration studies for the Timepix3 hybrid pixel detector in electron microscopy

Yves Auad, Jassem Baaboura, Jean-Denis Blazit +4

Direct electron detection is currently revolutionizing many fields of electron microscopy due to its lower noise, its reduced point-spread function, and its increased quantum effic…

physics.ins-det2022

Design and implementation of a device based on an off-axis parabolic mirror to perform luminescence experiments in a scanning tunneling microscope

Ricardo Javier Peña Román, Yves Auad, Lucas Grasso +5

We present the design, implementation, and illustrative results of a light collection/injection strategy based on an off-axis parabolic mirror collector for a low-temperature Scann…

cond-mat.mes-hall2019

Tailored nanoscale plasmon-enhanced vibrational electron spectroscopy

Luiz H. G. Tizei, Vahagn Mkhitaryan, Hugo Lourenço-Martins +12

Vibrational optical spectroscopies can be enhanced by surface plasmons to reach molecular-sized limits of detection and characterization. The level of enhancement strongly depends…

physics.app-ph2019

Spatial and spectral dynamics in STEM hyperspectral imaging using random scan patterns

Alberto Zobelli, Steffi Y. Woo, Luiz H. G. Tizei +6

The evolution of the scanning modules for scanning transmission electron microscopes (STEM) has realized the possibility to generate arbitrary scan pathways, an approach currently…

physics.optics2024

Selective probing of longitudinal and transverse plasmon modes with electron phase-matching

Franck Aguilar, Hugo Lourenço-Martins, Damián Montero +3

The optical properties of metallic nanoparticles are dominated by localized surface plasmons (LSPs). Their properties only depend on the constituting material, the size and shape o…

physics.ins-det2017

Development of a high brightness ultrafast Transmission Electron Microscope based on a laser-driven cold field emission source

Florent Houdellier, Giuseppe M. Caruso, Sébastien Weber +2

We report on the development of an ultrafast Transmission Electron Microscope based on a cold field emission source which can operate in either DC or ultrafast mode. Electron emiss…

physics.optics2026

Absolute measurement of the intrinsic helicity in nanophotonics

Malo Bézard, Simon Garrigou, Jérémie Béal +5

Helicity is a universal quantity describing the internal rotation of an object or a field. Whether it characterizes fundamental properties such as the spin of elementary particles…