A5016586014- Advanced Electron Microscopy Techniques and Applications
- Laser-Matter Interactions and Applications
- Photonic and Optical Devices
- Electron and X-Ray Spectroscopy Techniques
- Mechanical and Optical Resonators
- Advanced Fluorescence Microscopy Techniques
- Advanced Fiber Laser Technologies
- Integrated Circuits and Semiconductor Failure Analysis
- Near-Field Optical Microscopy
- Quantum Information and Cryptography
- Force Microscopy Techniques and Applications
- Magnetic properties of thin films
- Quantum optics and atomic interactions
- Laser-Plasma Interactions and Diagnostics
- Ion-surface interactions and analysis
- Plasmonic and Surface Plasmon Research
- Photonic Crystals and Applications
- Advanced X-ray Imaging Techniques
- Orbital Angular Momentum in Optics
- Photocathodes and Microchannel Plates
- Magneto-Optical Properties and Applications
- Cold Atom Physics and Bose-Einstein Condensates
- Theoretical and Computational Physics
- Laser Design and Applications
- Nonlinear Optical Materials Studies
Max Planck Institute for Dynamics and Self-Organization
2023-2024
Max Planck Institute for Multidisciplinary Sciences
2022-2024
University of Göttingen
2015-2024
Max Planck Institute for Biophysical Chemistry
2020-2022
Intelligent Transport Systems Niedersachsen
2020
Carl von Ossietzky Universität Oldenburg
2019
Lockheed Martin (United States)
2018
Dow Chemical (Canada)
2018
Solvay (Belgium)
2018
Samsung (United States)
2018
We present the development of first ultrafast transmission electron microscope (UTEM) driven by localized photoemission from a field emitter cathode. describe implementation instrument, photoemitter concept and quantitative beam parameters achieved. Establishing new source for TEM, Göttingen UTEM employs nano-localized linear Schottky emitter, which enables operation with freely tunable temporal structure, continuous wave to femtosecond pulsed mode. Using this emission mechanism, we achieve...
Abstract Integrated photonics facilitates extensive control over fundamental light–matter interactions in manifold quantum systems including atoms 1 , trapped ions 2,3 dots 4 and defect centres 5 . Ultrafast electron microscopy has recently made free-electron beams the subject of laser-based manipulation characterization 6–11 enabling observation walks 12–14 attosecond pulses 10,15–17 holographic electromagnetic imaging 18 Chip-based 19,20 promises unique applications nanoscale sensing but...
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...
Abstract While correlated electrons are at the heart of many phenomena in condensed matter, as well atomic and molecular physics, Coulomb interactions free-electron beams generally considered detrimental. Here, we demonstrate generation Coulomb-correlated pair, triple quadruple states free by femtosecond photoemission from a nanoscale field emitter inside transmission electron microscope. Event-based spectroscopy allows spatial spectral characterization ensemble emitted each laser pulse. We...
The short de Broglie wavelength and strong interaction empower free electrons to probe structures excitations in materials biomolecules. Recently, electron-photon interactions have enabled new optical manipulation schemes for electron beams. In this work, we demonstrate the of with nonlinear states inside a photonic chip–based microresonator. Optical parametric processes give rise spatiotemporal pattern formation corresponding coherent or incoherent frequency combs. We couple such...
This paper demonstrates a laser-based and femtosecond-switchable inelastic electron beam splitter. Coherent optical phase modulation of 200-keV electrons at thin electron-transparent membrane is used to prepare high-purity three-dimensional momentum superposition state, which characterized in energy space.
Magnetic topological defects, such as vortices and Skyrmions, can be stabilized equilibrium structures in nanoscale geometries by tailored intrinsic magnetic interactions. Here, employing rapid quench conditions, we report the observation of a light-induced metastable texture, which consists dense network antivortices. Our results demonstrate emergence ordering mechanisms quenched optically driven systems, may give general access to novel on nanometer length scales.
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...
Temporally shaping the density of electron beams using light forms basis for a wide range established and emerging technologies, including free-electron lasers attosecond microscopy. The modulation depth compressed pulses is key figure merit limiting applications. In this work, we present an approach generating background-free pulse trains by sequential inelastic electron-light scattering. Harnessing quantum interference in fractional Talbot effect, suppress unwanted background compression...
Tip-based photoemission electron sources offer unique properties for ultrafast imaging, diffraction, and spectroscopy experiments with highly coherent few-electron pulses. Extending this approach to increased bunch-charges requires a comprehensive experimental study on Coulomb interactions in nanoscale pulses their impact beam quality. For laser-driven Schottky field emitter, we assess the transverse longitudinal pulse an transmission microscope at high current density. A quantitative...
The control of optically driven high-frequency strain waves in nanostructured systems is an essential ingredient for the further development nanophononics. However, broadly applicable experimental means to quantitatively map such structural distortion on their intrinsic ultrafast time and nanometer length scales are still lacking. Here, we introduce convergent beam electron diffraction (U-CBED) with a nanoscale probe quantitative retrieval time-dependent local tensor. We demonstrate its...
Novel time-resolved imaging techniques for the investigation of ultrafast nanoscale magnetization dynamics are indispensable further developments in light-controlled magnetism. Here, we introduce femtosecond Lorentz microscopy, achieving a spatial resolution below 100 nm and temporal 700 fs, which gives access to transiently excited state spin system on timescales its subsequent relaxation dynamics. We demonstrate capabilities this technique by spatio-temporally mapping light-induced...
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...
Abstract We demonstrate photoassisted cold field emission (PFE) from a tungsten tip induced by tunable-wavelength low-power femtosecond laser excitation. The current the apex of (310)-oriented single-crystalline emitter is shown to linearly depend on incident power, while effective work function reduced respective photon energy. Our results promote implementation linear regime in laser-triggered for ultrafast transmission electron microscopy.
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.
Abstract The spatial features of ultrafast changes in magnetic textures carry detailed information on microscopic couplings and energy transport mechanisms. Electrons excel imaging such picosecond or shorter processes at nanometer length scales. We review the range physical interactions that produce contrast with electrons, specifically highlight recent emergence Lorentz transmission electron microscopy. From fundamental involved demagnetization extremely short timescales to skyrmion-based...
We report on the observation of Coulomb-correlated pair, triple, and quadruple free-electron states in a transmission electron microscope generated by femtosecond photoemission from nanoscale field emitter. The number exhibit energy momentum correlations about two electronvolts caused strong acceleration-enhanced inter-particle exchange. State-sorted beam caustics reveal longitudinal source increase shift. demonstrate electric-field control transverse against correlations. In conjunction...