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de Raadt TCH, Franssen JGH, Luiten OJ. Subpicosecond Ultracold Electron Source. PHYSICAL REVIEW LETTERS 2023; 130:205001. [PMID: 37267545 DOI: 10.1103/physrevlett.130.205001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Revised: 03/01/2023] [Accepted: 03/29/2023] [Indexed: 06/04/2023]
Abstract
We present the first observation of subpicosecond electron bunches from an ultracold electron source. This source is based on near-threshold, two-step, femtosecond photoionization of laser-cooled rubidium gas in a grating magneto-optical trap. Bunch lengths as short as 735±7 fs (rms) have been measured in the self-compression point of the source by means of ponderomotive scattering of the electrons by a 25 fs, 800 nm laser pulse. The observed temporal structure of the electron bunch depends on the central wavelength of the ionization laser pulse, in agreement with detailed simulations of the atomic photoionization process. This shows that the bunch length limit imposed by the atomic photoionization process has been reached.
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Affiliation(s)
- T C H de Raadt
- Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, Netherlands
| | - J G H Franssen
- Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, Netherlands
| | - O J Luiten
- Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, Netherlands
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2
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García
de Abajo FJ, Di Giulio V. Optical Excitations with Electron Beams: Challenges and Opportunities. ACS PHOTONICS 2021; 8:945-974. [PMID: 35356759 PMCID: PMC8939335 DOI: 10.1021/acsphotonics.0c01950] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 02/17/2021] [Accepted: 02/19/2021] [Indexed: 05/20/2023]
Abstract
Free electron beams such as those employed in electron microscopes have evolved into powerful tools to investigate photonic nanostructures with an unrivaled combination of spatial and spectral precision through the analysis of electron energy losses and cathodoluminescence light emission. In combination with ultrafast optics, the emerging field of ultrafast electron microscopy utilizes synchronized femtosecond electron and light pulses that are aimed at the sampled structures, holding the promise to bring simultaneous sub-Å-sub-fs-sub-meV space-time-energy resolution to the study of material and optical-field dynamics. In addition, these advances enable the manipulation of the wave function of individual free electrons in unprecedented ways, opening sound prospects to probe and control quantum excitations at the nanoscale. Here, we provide an overview of photonics research based on free electrons, supplemented by original theoretical insights and discussion of several stimulating challenges and opportunities. In particular, we show that the excitation probability by a single electron is independent of its wave function, apart from a classical average over the transverse beam density profile, whereas the probability for two or more modulated electrons depends on their relative spatial arrangement, thus reflecting the quantum nature of their interactions. We derive first-principles analytical expressions that embody these results and have general validity for arbitrarily shaped electrons and any type of electron-sample interaction. We conclude with some perspectives on various exciting directions that include disruptive approaches to noninvasive spectroscopy and microscopy, the possibility of sampling the nonlinear optical response at the nanoscale, the manipulation of the density matrices associated with free electrons and optical sample modes, and appealing applications in optical modulation of electron beams, all of which could potentially revolutionize the use of free electrons in photonics.
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Affiliation(s)
- F. Javier García
de Abajo
- ICFO-Institut
de Ciencies Fotoniques, The Barcelona Institute
of Science and Technology, 08860 Castelldefels, Barcelona, Spain
- ICREA-Institució
Catalana de Recerca i Estudis Avançats, Passeig Lluís Companys 23, 08010 Barcelona, Spain
- E-mail:
| | - Valerio Di Giulio
- ICFO-Institut
de Ciencies Fotoniques, The Barcelona Institute
of Science and Technology, 08860 Castelldefels, Barcelona, Spain
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Pan Y, Zhang B, Gover A. Anomalous Photon-Induced Near-Field Electron Microscopy. PHYSICAL REVIEW LETTERS 2019; 122:183204. [PMID: 31144903 DOI: 10.1103/physrevlett.122.183204] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Indexed: 06/09/2023]
Abstract
We reveal the classical and quantum regimes of free electron interaction with radiation, common to the general variety of radiation sources (e.g., a Smith-Purcell radiation), the dielectric laser accelerator, and photo-induced near-field electron microscopy (PINEM). Modeling the electron with initial conditions of a coherent quantum electron wave packet, its topology in phase space uniquely defines a universal distinction of three interaction regimes: point-particle-like acceleration, a quantum wave function (PINEM), and a newly reported regime of anomalous PINEM (APINEM). The quantum interference beat of APINEM is capable of improving the spectral resolution of postselective electron microscopy. The particle-wave duality transition between regimes reveals the history-dependent nature of quantum electron interaction with light.
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Affiliation(s)
- Yiming Pan
- Department of Physics of Complex Systems, Weizmann Institute of Science, Rehovot 76100, Israel
- Department of Electrical Engineering Physical Electronics, Tel Aviv University, Ramat Aviv 69978, Israel
| | - Bin Zhang
- National Laboratory of Solid State Microstructures and School of Physics, Nanjing University, Nanjing 210093, China
| | - Avraham Gover
- Department of Electrical Engineering Physical Electronics, Tel Aviv University, Ramat Aviv 69978, Israel
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Angioi A, Di Piazza A. Quantum Limitation to the Coherent Emission of Accelerated Charges. PHYSICAL REVIEW LETTERS 2018; 121:010402. [PMID: 30028155 DOI: 10.1103/physrevlett.121.010402] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Revised: 04/24/2018] [Indexed: 06/08/2023]
Abstract
Accelerated charges emit electromagnetic radiation. According to classical electrodynamics, if the charges move along sufficiently close trajectories they emit coherently; i.e., their emitted energy scales quadratically with their number rather than linearly. By investigating the emission by a two-electron wave packet in the presence of an electromagnetic plane wave within strong-field QED, we show that quantum effects deteriorate the coherence predicted by classical electrodynamics even if the typical quantum nonlinearity parameter of the system is much smaller than unity. We explain this result by observing that coherence effects are also controlled by a new quantum parameter which relates the recoil undergone by the electron to the width of its wave packet in momentum space.
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Affiliation(s)
- A Angioi
- Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany
| | - A Di Piazza
- Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany
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van Rens J, Verhoeven W, Franssen J, Lassise A, Stragier X, Kieft E, Mutsaers P, Luiten O. Theory and particle tracking simulations of a resonant radiofrequency deflection cavity in TM 110 mode for ultrafast electron microscopy. Ultramicroscopy 2018; 184:77-89. [DOI: 10.1016/j.ultramic.2017.10.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Revised: 10/06/2017] [Accepted: 10/10/2017] [Indexed: 11/17/2022]
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Abela R, Beaud P, van Bokhoven JA, Chergui M, Feurer T, Haase J, Ingold G, Johnson SL, Knopp G, Lemke H, Milne CJ, Pedrini B, Radi P, Schertler G, Standfuss J, Staub U, Patthey L. Perspective: Opportunities for ultrafast science at SwissFEL. STRUCTURAL DYNAMICS (MELVILLE, N.Y.) 2017; 4:061602. [PMID: 29376109 PMCID: PMC5758366 DOI: 10.1063/1.4997222] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2017] [Accepted: 10/17/2017] [Indexed: 05/03/2023]
Abstract
We present the main specifications of the newly constructed Swiss Free Electron Laser, SwissFEL, and explore its potential impact on ultrafast science. In light of recent achievements at current X-ray free electron lasers, we discuss the potential territory for new scientific breakthroughs offered by SwissFEL in Chemistry, Biology, and Materials Science, as well as nonlinear X-ray science.
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Affiliation(s)
- Rafael Abela
- SwissFEL, Paul-Scherrer Institute, 5232 Villigen PSI, Switzerland
| | - Paul Beaud
- SwissFEL, Paul-Scherrer Institute, 5232 Villigen PSI, Switzerland
| | - Jeroen A van Bokhoven
- Laboratory for Catalysis and Sustainable Chemistry, Paul-Scherrer Institute, 5232 Villigen PSI, and Department of Chemistry, ETH-Zürich, 8093 Zürich, Switzerland
| | - Majed Chergui
- Laboratoire de Spectroscopie Ultrarapide (LSU) and Lausanne Centre for Ultrafast Science (LACUS), Ecole Polytechnique Fédérale de Lausanne (EPFL), ISIC-FSB, Station 6, 1015 Lausanne, Switzerland
| | - Thomas Feurer
- Institute of Applied Physics, University of Bern, Bern, Switzerland
| | - Johannes Haase
- Laboratory for Catalysis and Sustainable Chemistry, Paul-Scherrer Institute, 5232 Villigen PSI, and Department of Chemistry, ETH-Zürich, 8093 Zürich, Switzerland
| | - Gerhard Ingold
- SwissFEL, Paul-Scherrer Institute, 5232 Villigen PSI, Switzerland
| | - Steven L Johnson
- Institute for Quantum Electronics, Eidgenössische Technische Hochschule (ETH) Zürich, 8093 Zurich, Switzerland
| | - Gregor Knopp
- SwissFEL, Paul-Scherrer Institute, 5232 Villigen PSI, Switzerland
| | - Henrik Lemke
- SwissFEL, Paul-Scherrer Institute, 5232 Villigen PSI, Switzerland
| | - Chris J Milne
- SwissFEL, Paul-Scherrer Institute, 5232 Villigen PSI, Switzerland
| | - Bill Pedrini
- SwissFEL, Paul-Scherrer Institute, 5232 Villigen PSI, Switzerland
| | - Peter Radi
- SwissFEL, Paul-Scherrer Institute, 5232 Villigen PSI, Switzerland
| | | | - Jörg Standfuss
- Division of Biology and Chemistry, Paul Scherrer Institut, 5232 Villigen PSI, Switzerland
| | - Urs Staub
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
| | - Luc Patthey
- SwissFEL, Paul-Scherrer Institute, 5232 Villigen PSI, Switzerland
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Chergui M, Collet E. Photoinduced Structural Dynamics of Molecular Systems Mapped by Time-Resolved X-ray Methods. Chem Rev 2017; 117:11025-11065. [DOI: 10.1021/acs.chemrev.6b00831] [Citation(s) in RCA: 150] [Impact Index Per Article: 21.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Majed Chergui
- Laboratoire
de Spectroscopie Ultrarapide (LSU), ISIC, and Lausanne Centre for
Ultrafast Science (LACUS), Faculté des Sciences de Base, Ecole Polytechnique Fédérale de Lausanne, Lausanne CH-1015, Switzerland
| | - Eric Collet
- Univ Rennes 1, CNRS, Institut de Physique de Rennes, UMR 6251, UBL, Rennes F-35042, France
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Franssen JGH, Luiten OJ. Improving temporal resolution of ultrafast electron diffraction by eliminating arrival time jitter induced by radiofrequency bunch compression cavities. STRUCTURAL DYNAMICS (MELVILLE, N.Y.) 2017; 4:044026. [PMID: 28580367 PMCID: PMC5446284 DOI: 10.1063/1.4984104] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Accepted: 05/12/2017] [Indexed: 06/07/2023]
Abstract
The temporal resolution of sub-relativistic ultrafast electron diffraction (UED) is generally limited by the radio frequency (RF) phase and amplitude jitter of the RF lenses that are used to compress the electron pulses. We theoretically show how to circumvent this limitation by using a combination of several RF compression cavities. We show that if powered by the same RF source and with a proper choice of RF field strengths, RF phases, and distances between the cavities, the combined arrival time jitter due to RF phase jitter of the cavities is cancelled at the compression point. We also show that the effect of RF amplitude jitter on the temporal resolution is negligible when passing through the cavity at a RF phase optimal for (de)compression. This will allow improvement of the temporal resolution in UED experiments to well below 100 fs.
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