Photonic flatband resonances for free-electron radiation

Nature, Год журнала: 2023, Номер 613(7942), С. 42 - 47

Опубликована: Янв. 4, 2023

Язык: Английский

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Attosecond electron microscopy of sub-cycle optical dynamics

Nature, Год журнала: 2023, Номер 619(7968), С. 63 - 67

Опубликована: Май 31, 2023

Язык: Английский

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Free-electron–light interactions in nanophotonics

Applied Physics Reviews, Год журнала: 2023, Номер 10(1)

Опубликована: Янв. 18, 2023

When impinging on optical structures or passing in their vicinity, free electrons can spontaneously emit electromagnetic radiation, a phenomenon generally known as cathodoluminescence. Free-electron radiation comes many guises: Cherenkov, transition, and Smith–Purcell but also electron scintillation, commonly referred to incoherent While those effects have been at the heart of fundamental discoveries technological developments high-energy physics past century, recent demonstration photonic nanophotonic systems has attracted great deal attention. Those arose from predictions that exploit nanophotonics for novel regimes, now becoming accessible thanks advances nanofabrication. In general, proper design enable shaping, control, enhancement free-electron any above-mentioned effects. opens way promising applications, such widely tunable integrated light sources x-ray THz frequencies, miniaturized particle accelerators, highly sensitive detectors. Here, we review emerging field nanophotonics. We first present unified framework describe light–matter interaction arbitrary systems. then show how this sheds physical underpinnings methods used control enhance radiation. Namely, points central role played by eigenmodes controlling output properties (e.g., frequency, directionality, polarization). experimental techniques characterize scanning transmission microscopes, which emerged platforms realization phenomena described review. further discuss various extract spectral, angular, polarization-resolved information conclude outlining directions field, including ultrafast quantum short-wavelength emitters ultraviolet soft topological states crystals.

Язык: Английский

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Advances in ultrafast plasmonics

Applied Physics Reviews, Год журнала: 2023, Номер 10(2)

Опубликована: Июнь 1, 2023

In the past 20 years, we have reached a broad understanding of many light-driven phenomena in nanoscale systems. The temporal dynamics excited states are instead quite challenging to explore, and, at same time, crucial study for origin fundamental physical and chemical processes. this review, examine current state prospects ultrafast driven by plasmons both from applied point view. This research area is referred as plasmonics represents an outstanding playground tailor control fast optical electronic processes nanoscale, such switching, single photon emission, strong coupling interactions photochemical reactions. Here, provide overview field describe methodologies monitor with timescales terms modeling experimental characterization. Various directions showcased, among others recent advances plasmon-driven chemistry multi-functional plasmonics, which charge, spin, lattice degrees freedom exploited active properties materials. As focus shifts development practical devices, all-optical transistors, also emphasize new materials applications highlight relativistic realm. latter promising potential fusion or particle light sources providing attosecond duration.

Язык: Английский

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Free-electron resonance transition radiation via Brewster randomness

Proceedings of the National Academy of Sciences, Год журнала: 2025, Номер 122(6)

Опубликована: Фев. 5, 2025

Free-electron radiation, such as Cherenkov radiation and transition can generate light at arbitrary frequencies is fundamental to diverse applications, ranging from electron microscopy, spectroscopy, lasers, particle detectors. Generally, the features of free-electron are stochastic when electrons interact with random media. Counterintuitively, here, we reveal a type that has both its intensity directionality invariant specific sorts long-range structural randomness. Essentially, this invariance enabled by Brewster effect judiciously engineered phase coherence condition emitted light, namely induced electron’s penetration through layered aperiodic nanostructure interfere constructively angle. As such, each constituent layer thickness fulfills condition, there always emergence resonance At resonant angle, further find could be enhanced orders magnitude readily increasing interface number. The revealed via randomness may offer feasible route explore more enticing photonic applications driven free electrons, sources previously unreachable spectral regimes, optical frequency combs, detectors, lasers.

Язык: Английский

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Cathodoluminescence excitation spectroscopy: Nanoscale imaging of excitation pathways

Science Advances, Год журнала: 2022, Номер 8(40)

Опубликована: Окт. 7, 2022

Following the lifespan of optical excitations from their creation to decay into photons is crucial in understanding materials properties. Macroscopically, techniques such as photoluminescence excitation spectroscopy provide unique information on photophysics with applications diverse quantum optics or photovoltaics. Materials and emission pathways are affected by nanometer scale variations directly impacting devices performances. However, they cannot be accessed, despite techniques, spectroscopies free electrons, having relevant spatial, spectral time resolution. Here, we explore two representative devices: plasmonic nanoparticles luminescent 2D layers. The analysis energy lost an exciting electron that coincident a visible-UV photon unveils towards light emission. This demonstrated for phase-locked interactions, localized surface plasmons, non-phase-locked ones, individual point defects. newly developed cathodoluminescence images transfer at scale. It widens toolset available nanoscale materials.

Язык: Английский

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Observation of 2D Cherenkov Radiation

Physical Review X, Год журнала: 2023, Номер 13(1)

Опубликована: Янв. 6, 2023

For over 80 years of research, the conventional description free-electron radiation phenomena, such as Cherenkov radiation, has remained unchanged: classical three-dimensional electromagnetic waves. Interestingly, in reduced dimensionality, properties are predicted to fundamentally change. Here, we present first observation surface waves, wherein free electrons emit narrow-bandwidth photonic quasiparticles propagating two-dimensions. The low dimensionality and narrow bandwidth effect enable identify quantized emission events through electron energy loss spectroscopy. Our results support recent theoretical prediction that do not always light can instead become entangled with photons they emit. two-dimensional interaction achieves quantum coupling strengths two orders magnitude larger than ever reported, reaching single-electron-single-photon regime for time electrons. findings pave way previously unexplored phenomena optics, facilitating bright, free-electron-based emitters heralded Fock states.

Язык: Английский

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Coulomb-correlated electron number states in a transmission electron microscope beam

Nature Physics, Год журнала: 2023, Номер 19(10), С. 1410 - 1417

Опубликована: Июнь 22, 2023

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 identify distinctive energy momentum correlations arising acceleration-enhanced interparticle exchange, revealing strong few-body an scale 2 eV. State-sorted beam caustics show discrete increase virtual source size longitudinal shift for few-electron states, associated with transverse correlations. observe field-controllable antibunching, attributed primarily to deflection. The pronounced characteristics these number allow filtering schemes that control statistical distribution pulse charge. In this way, fraction specific can be actively suppressed or enhanced, facilitating preparation highly non-Poissonian microscopy lithography, including future heralding multi-electron probing.

Язык: Английский

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Creation of Optical Cat and GKP States Using Shaped Free Electrons

Physical Review X, Год журнала: 2023, Номер 13(3)

Опубликована: Июль 6, 2023

A new approach to generating quantum states of light most suitable for robust computing draws on one the basic interactions in physics---the interaction between free electrons and photons.

Язык: Английский

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Free-electron interaction with nonlinear optical states in microresonators

Science, Год журнала: 2024, Номер 383(6679), С. 168 - 173

Опубликована: Янв. 11, 2024

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 “microcombs” beams, their fingerprints spectra, achieve ultrafast temporal gating beam. Our work demonstrates ability access solitons an microscope extends use microcombs control imaging spectroscopy.

Язык: Английский

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