A5060050233- Advanced Electron Microscopy Techniques and Applications
- Plasmonic and Surface Plasmon Research
- Gold and Silver Nanoparticles Synthesis and Applications
- Electron and X-Ray Spectroscopy Techniques
- Near-Field Optical Microscopy
- Photonic and Optical Devices
- Mechanical and Optical Resonators
- Force Microscopy Techniques and Applications
- Quantum Information and Cryptography
- Integrated Circuits and Semiconductor Failure Analysis
- Surface and Thin Film Phenomena
- Advanced biosensing and bioanalysis techniques
- Orbital Angular Momentum in Optics
- Advanced Fiber Laser Technologies
- Laser-Matter Interactions and Applications
- Advanced Fluorescence Microscopy Techniques
- Spectroscopy and Quantum Chemical Studies
- Nanowire Synthesis and Applications
- Quantum Dots Synthesis And Properties
- Quantum optics and atomic interactions
- Molecular Junctions and Nanostructures
- Laser-Plasma Interactions and Diagnostics
- X-ray Spectroscopy and Fluorescence Analysis
- Cold Atom Physics and Bose-Einstein Condensates
- Electronic and Structural Properties of Oxides
University of Göttingen
2019-2024
Centre d’Élaboration de Matériaux et d’Études Structurales
2021-2024
Université de Toulouse
2023-2024
Centre National de la Recherche Scientifique
2013-2024
Max Planck Institute for Dynamics and Self-Organization
2023-2024
Max Planck Institute for Multidisciplinary Sciences
2022-2024
Laboratoire d'Optique Appliquée
2024
Max Planck Institute for the Study of Religious and Ethnic Diversity
2022
Laboratoire de physique des Solides
2016-2021
Max Planck Institute for Biophysical Chemistry
2020-2021
Advancing quantum information, communication and sensing relies on the generation control of correlations in complementary degrees freedom. Here, we demonstrate preparation electron-photon pair states using phase-matched interaction free electrons with evanescent vacuum field a photonic-chip-based optical microresonator. Spontaneous inelastic scattering produces intracavity photons coincident energy-shifted electrons. Harnessing these pairs for correlation-enhanced imaging, achieve...
Abstract Time-resolved electron microscopy aims to track nanoscale excitations and dynamic states of matter at a temporal resolution ultimately reaching the attosecond regime. Periodically time-varying fields in an illuminated specimen cause free-electron inelastic scattering, which enables spectroscopic imaging near-field intensities. However, access evolution structures within cycle light requires sensitivity optical phase. Here we introduce homodyne detection as universally applicable...
Plasmonics, the science and technology of interaction light with metallic objects, is fundamentally changing way we can detect, generate manipulate light. Although field progressing swiftly, thanks to availability nanoscale manufacturing analysis methods, fundamental properties such as plasmonic excitations' symmetries cannot be accessed directly, leading a partial, sometimes incorrect, understanding their properties. Here overcome this limitation by deliberately shaping wave function an...
Polaritons are compositional light-matter quasiparticles that have enabled remarkable breakthroughs in quantum and nonlinear optics, as well material science. Recently, plasmon–exciton polaritons (plexcitons) been realized hybrid systems composed of transition metal dichalcogenide (TMDC) materials nanoparticles, expanding polaritonic concepts to room temperature nanoscale also benefit from the exotic properties TMDC materials. Despite enormous progress understanding TMDC-based plexcitons...
We demonstrate spatially-resolved measurements of spontaneous and stimulated electron-photon interactions in nanoscale optical near fields using electron energy-loss spectroscopy (EELS), cathodoluminescence (CL), photon-induced near-field microscopy (PINEM). Specifically, we study resonant surface plasmon modes that are tightly confined to the tip apexes an Au nanostar, enabling a direct correlation EELS, CL, PINEM on same physical structure at nanometer length scale. Complemented by...
Coupling molecular excitons and localized surface plasmons in hybrid nanostructures leads to appealing, tunable optical properties. In this respect, the knowledge about excitation dynamics of a quantum emitter close plasmonic nanoantenna is importance from fundamental practical points view. We address here effect excited electron tunneling into metallic nanoparticle(s) response. When nanoparticle, state on becomes short-lived because electronic coupling with metal conduction band states....
Atomic vibrations and phonons are an excellent source of information on nanomaterials that we can access through a variety methods including Raman scattering, infrared spectroscopy, electron energy-loss spectroscopy (EELS). In the presence plasmon local field, strongly modified and, in particular, their dipolar strengths highly enhanced, thus rendering scattering extremely sensitive techniques. Here, experimentally demonstrate interaction between relativistic vibrational modes nanostructures...
Abstract This conference proceeding reports on the usage and applications of a high numerical aperture mirror for cathodoluminescence other photon-based spectroscopies in scanning transmission electron microscope.
We investigated the optical properties of localized surface plasmons with different orders in individual silver nanotriangles sizes by electron energy loss spectroscopy (EELS) and cathodoluminescence (CL) same scanning transmission microscope. EELS CL spectral imaging within give information about extinction scattering from nanostructures. As measured both techniques, first two order modes showed similar spatial distributions. However, appearances slightly resonant energies were confirmed...
The study of surface phonons, collective atomic vibrations localized on the solids, has long been helped by insights from experiments plasmons, their electronic counterparts. A new analysis takes these analogies in opposite direction, using modern concepts for plasmons to explain current phonon experiments.
Circular dichroism spectroscopy is an essential technique for understanding molecular structure and magnetic materials, but spatial resolution limited by the wavelength of light, sensitivity sufficient single-molecule challenging. We demonstrate that electrons can efficiently measure interaction between circularly polarized light chiral materials with deeply sub-wavelength resolution. By scanning a nanometer-sized focused electron beam across optically-excited nanostructure measuring energy...
In electron microscopy, detailed insights into nanoscale optical properties of materials are gained by spontaneous inelastic scattering leading to electron-energy loss and cathodoluminescence. Stimulated in the presence external sample excitation allows for mode- polarization-selective photon-induced near-field microscopy (PINEM). This process imprints a spatial phase profile inherited from fields onto wave function probing electrons. Here, we introduce Lorentz-PINEM full-field, non-invasive...
The structural and optical properties of axial GaN/InGaN/GaN nanowire heterostructures with high InN molar fractions grown by molecular beam epitaxy have been studied at the nanoscale a combination electron microscopy, extended x-ray absorption fine structure nano-cathodoluminescence techniques. up to 50% successfully incorporated without defects, as evidence potentialities for practical device realisation in such composition range. Taking advantage N-polarity self-nucleated GaN NWs on...
Whispering-gallery mode resonators host multiple trapped narrow-band circulating optical resonances that find applications in quantum electrodynamics, optomechanics, and sensing. However, the spherical symmetry low field leakage of dielectric microspheres make it difficult to probe their high-quality modes using far-field radiation. Even so, local enhancement from metallic nanoparticles (MNPs) coupled can interface far bounded cavity modes. In this work, we study interaction between...
The local density of optical states governs an emitters lifetime and quantum yield through the Purcell effect. It can be modified by a surface plasmon electromagnetic field, but such field has spatial extension limited to few hundreds nanometers, which complicates use methods spatially probe emitter-plasmon coupling. Here we show that combination electron-based imaging, spectroscopies photon-based correlation spectroscopy enables measurement effect with nanometer nanosecond spatio-temporal...
In the last decades, blossoming of experimental breakthroughs in domain electron energy loss spectroscopy (EELS) has triggered a variety theoretical developments. Those have to deal with completely different situations, from atomically resolved phonon mapping circular dichroism passing by surface plasmon mapping. All them rely on very physical approximations and not yet been reconciled, despite early attempts do so. As an effort that direction, we report development scalar relativistic...
We investigate, both experimentally and theoretically, the inelastic interaction between fast electrons electromagnetic field scattered by metallic apertures nanostructures on dielectric membranes using photon-induced near-field electron microscopy. The experiments, performed in a high-brightness ultrafast transmission microscope, gold silicon nitride reveal strong modulations of electron–light coupling strength. demonstrate that this effect results from combined action electric aperture...
We implement attosecond electron microscopy in a TEM to measure the optical near-field of plasmonic nanoprism with 54 as (FWHM) temporal and few-nm spatial resolution, demonstrating free-electron homodyne detection.
Plasmonic resonator arrays have attracted a great interest as platform to enhance light–matter interaction and been examined for their applicability various types of optical devices, such sensors, light emitter, photocatalyst, name few. In plasmonic array, localized propagating plasmon modes can hybridize, which is known result in an anticrossing the bands dispersion curves. However, it was so far unclear how modal symmetry affects hybridization, especially when occurs at specific reciprocal...
The optical properties of metallic nanoparticles are dominated by localized surface plasmons (LSPs). Their depend on the constituting material, size, and shape nano-object as well its surrounding medium. In anisotropic structures, such nanorods, two families modes generally exist, transverse longitudinal. spectral spatial overlaps usually impede their separate measurements in electron energy loss spectroscopy (EELS). this work, we propose three different strategies to overcome difficulty...
With the help of electron energy loss spectroscopy (EELS) in a scanning transmission microscope (STEM) and boundary element method (BEM) simulations, we have shown that silver nanocross can be used to tune plasmon modes especially higher order very controlled manner. Morphing nanorod by growing another arm along perpendicular bisector lead spectacular evolution various EEL spectra. One keep mode fixed while bringing next close it, or even make it cross. This allows one control relative...
Plasmonic crystals are well known to have band structure including a gap, enabling the control of surface plasmon propagation and confinement. The dispersion relation bulk has been generally measured by momentum-resolved spectroscopy using far field optical techniques while defects introduced in separately investigated near imaging so far. Particularly, defect related energy levels plasmonic gap not observed experimentally. In order investigate such localized mode, we performed electron...