531 citations · 1.2k across the 19 of their papers we have counts for
22 papers
Cathodoluminescence Enhancement Mechanisms in Silica Microspheres
Hadar Aharon, Zahava Barkay, Sophie Meuret +1
Cathodoluminescence (CL) enables optical-frequency analysis of samples with nanometer resolutions, originating from the interaction of a focused electron beam with radiative electr…
Elastic Quantum Coupling Between Free Electrons and Photons
Dingguo Zheng, Ofer Kfir
The quantum coupling between free-electrons and photons enables applying quantum optics techniques in electron microscopy. Here, we formulate the elastic electron-photon quantum co…
Revealing domain wall stability during ultrafast demagnetization
Hung-Tzu Chang, Sergey Zayko, Timo Schmidt +5
The ultrafast control of nanoscale spin textures such as magnetic domain walls or skyrmions is essential for advancing high-speed, high-density spintronics. However, imaging their…
Light's symmetry, asymmetry, and their role in nonlinear optics and ultrafast phenomena
Ofer Neufeld, Matan Even Tzur, Ofer Kfir +2
The analysis of symmetries is extremely useful across science. In Physics, symmetries are used to derive conservation laws and selection rules for transitions in interacting system…
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…
On spatial electron-photon entanglement
Eitan Kazakevich, Hadar Aharon, Ofer Kfir
Free electron beams and their quantum coupling with photons is attracting a rising interest due to the basic questions it addresses and the cutting-edge technology these particles…
2024 Roadmap on Magnetic Microscopy Techniques and Their Applications in Materials Science
D. V. Christensen, U. Staub, T. R. Devidas +50
Considering the growing interest in magnetic materials for unconventional computing, data storage, and sensor applications, there is active research not only on material synthesis…
Sub-Terahertz Nearfields for Electron-Pulse Compression
Yarden Mazor, Ofer Kfir
The advent of ultrafast science with pulsed electron beams raised the need in controlling the temporal features of the electron pulses. One promising suggestion is the nano-selecti…
Quantum state heralding using photonic integrated circuits with free electrons
Guanhao Huang, Nils J. Engelsen, Ofer Kfir +2
Recently, integrated photonic circuits have brought new capabilities to electron microscopy and been used to demonstrate efficient electron phase modulation and electron-photon cor…
Modulation of Cathodoluminescence Emission by Interference with External Light
Valerio Di Giulio, Ofer Kfir, Claus Ropers +1
Spontaneous processes triggered in a sample by free electrons are commonly regarded as incoherent, and therefore unable to interfere with external light sources. Here, we challenge…
Implementing strong interference in ultrathin film top absorbers for tandem solar cells
Yifat Piekner, Hen Dotan, Anton Tsyganok +4
Strong interference in ultrathin film semiconductor absorbers on metallic back reflectors has been shown to enhance the light harvesting efficiency of solar cell materials. However…
Ultrafast high-harmonic nanoscopy of magnetization dynamics
Sergey Zayko, Ofer Kfir, Michael Heigl +4
Light-induced magnetization changes, such as all-optical switching, skyrmion nucleation, and intersite spin transfer, unfold on temporal and spatial scales down to femtoseconds and…
Optical coherence transfer mediated by free electrons
Ofer Kfir, Valerio Di Giulio, F. Javier García de Abajo +1
We investigate theoretically the quantum-coherence properties of the cathodoluminescence (CL) emission produced by a temporally modulated electron beam. Specifically, we consider t…
Chiral high-harmonic generation and spectroscopy on solid surfaces using polarization-tailored strong fields
Tobias Heinrich, Marco Taucer, Ofer Kfir +4
Strong-field methods in solids enable new strategies for ultrafast nonlinear spectroscopy and provide all-optical insights into the electronic properties of condensed matter in rec…
Probing chirality with inelastic electron-light scattering
Tyler R. Harvey, Jan-Wilke Henke, Ofer Kfir +4
Circular dichroism spectroscopy is an essential technique for understanding molecular structure and magnetic materials, but spatial resolution is limited by the wavelength of light…
Controlling free electrons with optical whispering-gallery modes
Ofer Kfir, Hugo Lourenço-Martins, Gero Storeck +5
Free-electron beams serve as uniquely versatile probes of microscopic structure and composition, and have repeatedly revolutionized atomic-scale imaging, from solid-state physics t…
Entanglements of electrons and cavity-photons in the strong coupling regime
Ofer Kfir
This work sets a road-map towards an experimental realization of strong coupling between free-electrons and photons, and analytically explores entanglement phenomena that emerge in…
Nanoscale Magnetic Imaging using Circularly Polarized High-Harmonic Radiation
Ofer Kfir, Sergey Zayko, Christina Nolte +10
This work demonstrates nanoscale magnetic imaging using bright circularly polarized high-harmonic radiation. We utilize the magneto-optical contrast of worm-like magnetic domains i…
High-order harmonics with frequency-varying polarization within each harmonic
Avner Fleischer, Ofer Kfir, Pavel Sidorenko +1
We predict high-order harmonics in which the polarization within the spectral bandwidth of each harmonic varies continuously and significantly. For example, the interaction of coun…
Generation of phase-matched circularly-polarized extreme ultraviolet high harmonics for magnetic circular dichroism spectroscopy
Ofer Kfir, Patrik Grychtol, Emrah Turgut +10
Circularly-polarized extreme UV and X-ray radiation provides valuable access to the structural, electronic and magnetic properties of materials. To date, this capability was availa…
Does high harmonic generation conserve angular momentum?
Avner Fleischer, Ofer Kfir, Tzvi Diskin +2
High harmonic generation (HHG) is a unique and useful process in which infrared or visible radiation is frequency up converted into the extreme ultraviolet and x ray spectral regio…
Self-trapped leaky waves in lattices: discrete and Bragg soleakons
Maxim Kozlov, Ofer Kfir, Oren Cohen
We propose lattice soleakons: self-trapped waves that self-consistently populate leaky modes of their self-induced defects in periodic potentials. Two types, discrete and Bragg, la…