1
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Bourgeois MR, Nixon AG, Chalifour M, Masiello DJ. Optical polarization analogs in inelastic free-electron scattering. SCIENCE ADVANCES 2023; 9:eadj6038. [PMID: 38117898 PMCID: PMC10732523 DOI: 10.1126/sciadv.adj6038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Accepted: 11/17/2023] [Indexed: 12/22/2023]
Abstract
Advances in the ability to manipulate free-electron phase profiles within the electron microscope have spurred development of quantum-mechanical descriptions of electron energy loss (EEL) processes involving transitions between phase-shaped transverse states. Here, we elucidate an underlying connection between two ostensibly distinct optical polarization analogs identified in EEL experiments as manifestations of the same conserved scattering flux. Our work introduces a procedure for probing general tensorial target characteristics including global mode symmetries and local polarization.
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Affiliation(s)
- Marc R. Bourgeois
- Department of Chemistry, University of Washington, Seattle, WA 98195, USA
| | - Austin G. Nixon
- Department of Chemistry, University of Washington, Seattle, WA 98195, USA
| | | | - David J. Masiello
- Department of Chemistry, University of Washington, Seattle, WA 98195, USA
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2
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Ederer M, Löffler S. Optimizing experimental parameters for orbital mapping. Ultramicroscopy 2023; 256:113866. [PMID: 37866278 DOI: 10.1016/j.ultramic.2023.113866] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Revised: 09/29/2023] [Accepted: 10/08/2023] [Indexed: 10/24/2023]
Abstract
A new material characterization technique is emerging for the transmission electron microscope (TEM). Using electron energy-loss spectroscopy, real space mappings of the underlying electronic transitions in the sample, so called orbital maps, can be produced. Thus, unprecedented insight into the electronic orbitals responsible for most of the electrical, magnetic and optical properties of bulk materials can be gained. However, the incredibly demanding requirements on spatial as well as spectral resolution paired with the low signal-to-noise ratio severely limits the day-to-day use of this new technique. With the use of simulations, we strive to alleviate these challenges as much as possible by identifying optimal experimental parameters. In this manner, we investigate representative examples of a transition metal oxide, a material consisting entirely of light elements, and an interface between two different materials to find and compare acceptable ranges for sample thickness, acceleration voltage and electron dose for a scanning probe as well as for parallel illumination.
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Affiliation(s)
- Manuel Ederer
- University Service Centre for Transmission Electron Microscopy, TU Wien, Wiedner Hauptstraße 8-10/E057-02, 1040 Wien, Austria.
| | - Stefan Löffler
- University Service Centre for Transmission Electron Microscopy, TU Wien, Wiedner Hauptstraße 8-10/E057-02, 1040 Wien, Austria
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3
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Rotunno E, Grillo V. Automatic Operation of Conventional and Innovative Hardware for Electron Microscopy. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2023; 29:1870-1871. [PMID: 37613959 DOI: 10.1093/micmic/ozad067.965] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/25/2023]
Affiliation(s)
- Enzo Rotunno
- Consiglio Nazionale delle Ricerche, Istituto NANO, Modena, Italy
| | - Vincenzo Grillo
- Consiglio Nazionale delle Ricerche, Istituto NANO, Modena, Italy
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4
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Konečná A, Rotunno E, Grillo V, García de Abajo FJ, Vanacore GM. Single-Pixel Imaging in Space and Time with Optically Modulated Free Electrons. ACS PHOTONICS 2023; 10:1463-1472. [PMID: 37215321 PMCID: PMC10197172 DOI: 10.1021/acsphotonics.3c00047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Indexed: 05/24/2023]
Abstract
Single-pixel imaging, originally developed in light optics, facilitates fast three-dimensional sample reconstruction as well as probing with light wavelengths undetectable by conventional multi-pixel detectors. However, the spatial resolution of optics-based single-pixel microscopy is limited by diffraction to hundreds of nanometers. Here, we propose an implementation of single-pixel imaging relying on attainable modifications of currently available ultrafast electron microscopes in which optically modulated electrons are used instead of photons to achieve subnanometer spatially and temporally resolved single-pixel imaging. We simulate electron beam profiles generated by interaction with the optical field produced by an externally programmable spatial light modulator and demonstrate the feasibility of the method by showing that the sample image and its temporal evolution can be reconstructed using realistic imperfect illumination patterns. Electron single-pixel imaging holds strong potential for application in low-dose probing of beam-sensitive biological and molecular samples, including rapid screening during in situ experiments.
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Affiliation(s)
- Andrea Konečná
- ICFO-Institut
de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Castelldefels, Barcelona 08860, Spain
- Central
European Institute of Technology, Brno University of Technology, 612 00 Brno, Czech Republic
| | - Enzo Rotunno
- Centro
S3, Istituto di Nanoscienze-CNR, 41125 Modena, Italy
| | | | - F. Javier García de Abajo
- ICFO-Institut
de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Castelldefels, Barcelona 08860, Spain
- ICREA-Institució
Catalana de Recerca i Estudis Avançats, Passeig Lluís Companys 23, 08010 Barcelona, Spain
| | - Giovanni Maria Vanacore
- Laboratory
of Ultrafast Microscopy for Nanoscale Dynamics (LUMiNaD), Department
of Materials Science, University of Milano-Bicocca, Via Cozzi 55, 20121 Milano, Italy
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5
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Tsesses S, Dahan R, Wang K, Bucher T, Cohen K, Reinhardt O, Bartal G, Kaminer I. Tunable photon-induced spatial modulation of free electrons. NATURE MATERIALS 2023; 22:345-352. [PMID: 36702889 DOI: 10.1038/s41563-022-01449-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Accepted: 11/26/2022] [Indexed: 06/18/2023]
Abstract
Spatial modulation of electron beams is an essential tool for various applications such as nanolithography and imaging, yet its conventional implementations are severely limited and inherently non-tunable. Conversely, proposals of light-driven electron spatial modulation promise tunable electron wavefront shaping, for example, using the mechanism of photon-induced near-field electron microscopy. Here we present tunable photon-induced spatial modulation of electrons through their interaction with externally controlled surface plasmon polaritons (SPPs). Using recently developed methods of shaping SPP patterns, we demonstrate a dynamic control of the electron beam with a variety of electron distributions and verify their coherence through electron diffraction. Finally, the nonlinearity stemming from energy post-selection provides us with another avenue for controlling the electron shape, generating electron features far below the SPP wavelength. Our work paves the way to on-demand electron wavefront shaping at ultrafast timescales, with prospects for aberration correction, nanofabrication and material characterization.
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Affiliation(s)
- Shai Tsesses
- Andrew and Erna Viterbi Department of Electrical Engineering, Technion, Israel Institute of Technology, Haifa, Israel
| | - Raphael Dahan
- Andrew and Erna Viterbi Department of Electrical Engineering, Technion, Israel Institute of Technology, Haifa, Israel
- Solid State Institute, Technion, Israel Institute of Technology, Haifa, Israel
| | - Kangpeng Wang
- Andrew and Erna Viterbi Department of Electrical Engineering, Technion, Israel Institute of Technology, Haifa, Israel
- Solid State Institute, Technion, Israel Institute of Technology, Haifa, Israel
- Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai, China
| | - Tomer Bucher
- Andrew and Erna Viterbi Department of Electrical Engineering, Technion, Israel Institute of Technology, Haifa, Israel
- Solid State Institute, Technion, Israel Institute of Technology, Haifa, Israel
| | - Kobi Cohen
- Andrew and Erna Viterbi Department of Electrical Engineering, Technion, Israel Institute of Technology, Haifa, Israel
| | - Ori Reinhardt
- Andrew and Erna Viterbi Department of Electrical Engineering, Technion, Israel Institute of Technology, Haifa, Israel
- Solid State Institute, Technion, Israel Institute of Technology, Haifa, Israel
| | - Guy Bartal
- Andrew and Erna Viterbi Department of Electrical Engineering, Technion, Israel Institute of Technology, Haifa, Israel
| | - Ido Kaminer
- Andrew and Erna Viterbi Department of Electrical Engineering, Technion, Israel Institute of Technology, Haifa, Israel.
- Solid State Institute, Technion, Israel Institute of Technology, Haifa, Israel.
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6
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Bertoni G, Rotunno E, Marsmans D, Tiemeijer P, Tavabi AH, Dunin-Borkowski RE, Grillo V. Near-real-time diagnosis of electron optical phase aberrations in scanning transmission electron microscopy using an artificial neural network. Ultramicroscopy 2023; 245:113663. [PMID: 36566529 DOI: 10.1016/j.ultramic.2022.113663] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Revised: 10/17/2022] [Accepted: 12/17/2022] [Indexed: 12/23/2022]
Abstract
The key to optimizing spatial resolution in a state-of-the-art scanning transmission electron microscope is the ability to measure and correct for electron optical aberrations of the probe-forming lenses precisely. Several diagnostic methods for aberration measurement and correction have been proposed, albeit often at the cost of relatively long acquisition times. Here, we illustrate how artificial intelligence can be used to provide near-real-time diagnosis of aberrations from individual Ronchigrams. The demonstrated speed of aberration measurement is important because microscope conditions can change rapidly. It is also important for the operation of MEMS-based hardware correction elements, which have less intrinsic stability than conventional electromagnetic lenses.
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Affiliation(s)
- Giovanni Bertoni
- Istituto Nanoscienze, Consiglio Nazionale delle Ricerche, Via G. Campi 213/A, 41125 Modena, Italy.
| | - Enzo Rotunno
- Istituto Nanoscienze, Consiglio Nazionale delle Ricerche, Via G. Campi 213/A, 41125 Modena, Italy.
| | - Daan Marsmans
- Thermo Fisher Scientific, PO Box 80066, 5600 KA Eindhoven, the Netherlands
| | - Peter Tiemeijer
- Thermo Fisher Scientific, PO Box 80066, 5600 KA Eindhoven, the Netherlands
| | - Amir H Tavabi
- Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons, Forschungszentrum Jülich, 52425 Jülich, Germany
| | - Rafal E Dunin-Borkowski
- Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons, Forschungszentrum Jülich, 52425 Jülich, Germany
| | - Vincenzo Grillo
- Istituto Nanoscienze, Consiglio Nazionale delle Ricerche, Via G. Campi 213/A, 41125 Modena, Italy
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7
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Planas XB, Ordóñez A, Lewenstein M, Maxwell AS. Ultrafast Imaging of Molecular Chirality with Photoelectron Vortices. PHYSICAL REVIEW LETTERS 2022; 129:233201. [PMID: 36563195 DOI: 10.1103/physrevlett.129.233201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Revised: 07/30/2022] [Accepted: 10/25/2022] [Indexed: 06/17/2023]
Abstract
Ultrafast imaging of molecular chirality is a key step toward the dream of imaging and interpreting electronic dynamics in complex and biologically relevant molecules. Here, we propose a new ultrafast chiral phenomenon exploiting recent advances in electron optics allowing access to the orbital angular momentum of free electrons. We show that strong-field ionization of a chiral target with a few-cycle linearly polarized 800 nm laser pulse yields photoelectron vortices, whose chirality reveals that of the target, and we discuss the mechanism underlying this phenomenon. Our Letter opens new perspectives in recollision-based chiral imaging.
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Affiliation(s)
- Xavier Barcons Planas
- ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels (Barcelona), Spain
| | - Andrés Ordóñez
- ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels (Barcelona), Spain
| | - Maciej Lewenstein
- ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels (Barcelona), Spain
- ICREA, Passeig de Lluís Companys 23, 08010 Barcelona, Spain
| | - Andrew S Maxwell
- ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels (Barcelona), Spain
- Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C, Denmark
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8
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Madan I, Leccese V, Mazur A, Barantani F, LaGrange T, Sapozhnik A, Tengdin PM, Gargiulo S, Rotunno E, Olaya JC, Kaminer I, Grillo V, de Abajo FJG, Carbone F, Vanacore GM. Ultrafast Transverse Modulation of Free Electrons by Interaction with Shaped Optical Fields. ACS PHOTONICS 2022; 9:3215-3224. [PMID: 36281329 PMCID: PMC9585634 DOI: 10.1021/acsphotonics.2c00850] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2022] [Indexed: 05/13/2023]
Abstract
Spatiotemporal electron-beam shaping is a bold frontier of electron microscopy. Over the past decade, shaping methods evolved from static phase plates to low-speed electrostatic and magnetostatic displays. Recently, a swift change of paradigm utilizing light to control free electrons has emerged. Here, we experimentally demonstrate arbitrary transverse modulation of electron beams without complicated electron-optics elements or material nanostructures, but rather using shaped light beams. On-demand spatial modulation of electron wavepackets is obtained via inelastic interaction with transversely shaped ultrafast light fields controlled by an external spatial light modulator. We illustrate this method for the cases of Hermite-Gaussian and Laguerre-Gaussian modulation and discuss their use in enhancing microscope sensitivity. Our approach dramatically widens the range of patterns that can be imprinted on the electron profile and greatly facilitates tailored electron-beam shaping.
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Affiliation(s)
- Ivan Madan
- Institute
of Physics, École Polytechnique Fédérale
de Lausanne, Lausanne, 1015, Switzerland
| | - Veronica Leccese
- Institute
of Physics, École Polytechnique Fédérale
de Lausanne, Lausanne, 1015, Switzerland
| | - Adam Mazur
- HOLOEYE
Photonics AG, Volmerstrasse 1, 12489 Berlin, Germany
| | - Francesco Barantani
- Institute
of Physics, École Polytechnique Fédérale
de Lausanne, Lausanne, 1015, Switzerland
- Department
of Quantum Matter Physics, University of
Geneva, 1211 Geneva, Switzerland
| | - Thomas LaGrange
- Institute
of Physics, École Polytechnique Fédérale
de Lausanne, Lausanne, 1015, Switzerland
| | - Alexey Sapozhnik
- Institute
of Physics, École Polytechnique Fédérale
de Lausanne, Lausanne, 1015, Switzerland
| | - Phoebe M. Tengdin
- Institute
of Physics, École Polytechnique Fédérale
de Lausanne, Lausanne, 1015, Switzerland
| | - Simone Gargiulo
- Institute
of Physics, École Polytechnique Fédérale
de Lausanne, Lausanne, 1015, Switzerland
| | - Enzo Rotunno
- Centro
S3, Istituto di Nanoscienze-CNR, 41125 Modena, Italy
| | | | - Ido Kaminer
- Department
of Electrical and Computer Engineering, Technion, Haifa 32000, Israel
| | | | - 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
| | - Fabrizio Carbone
- Institute
of Physics, École Polytechnique Fédérale
de Lausanne, Lausanne, 1015, Switzerland
| | - Giovanni Maria Vanacore
- Department
of Materials Science, University of Milano-Bicocca, Via Cozzi 55, 20126 Milano, Italy
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9
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Bourgeois MR, Nixon AG, Chalifour M, Beutler EK, Masiello DJ. Polarization-Resolved Electron Energy Gain Nanospectroscopy With Phase-Structured Electron Beams. NANO LETTERS 2022; 22:7158-7165. [PMID: 36036765 DOI: 10.1021/acs.nanolett.2c02375] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Free-electron-based measurements in scanning transmission electron microscopes (STEMs) reveal valuable information on the broadband spectral responses of nanoscale systems with deeply subdiffraction limited spatial resolution. Leveraging recent advances in manipulating the spatial phase profile of the transverse electron wavefront, we theoretically describe interactions between the electron probe and optically stimulated nanophotonic targets in which the probe gains energy while simultaneously transitioning between transverse states with distinct phase profiles. Exploiting the selection rules governing such transitions, we propose phase-shaped electron energy gain nanospectroscopy for probing the 3D polarization-resolved response field of an optically excited target with nanoscale spatial resolution. Considering ongoing instrumental developments, polarized generalizations of STEM electron energy loss and gain measurements hold the potential to become powerful tools for fundamental studies of quantum materials and their interaction with nearby nanostructures supporting localized surface plasmon or phonon polaritons as well as for noninvasive imaging and nanoscale 3D field tomography.
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Affiliation(s)
- Marc R Bourgeois
- Department of Chemistry, University of Washington, Seattle, Washington 98195, United States
| | - Austin G Nixon
- Department of Chemistry, University of Washington, Seattle, Washington 98195, United States
| | - Matthieu Chalifour
- Department of Physics, University of Washington, Seattle, Washington 98195, United States
| | - Elliot K Beutler
- Department of Chemistry, University of Washington, Seattle, Washington 98195, United States
| | - David J Masiello
- Department of Chemistry, University of Washington, Seattle, Washington 98195, United States
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10
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Rosi P, Clausen A, Weber D, Tavabi AH, Frabboni S, Tiemeijer P, Dunin-Borkowski RE, Rotunno E, Grillo V. Automatic Alignment of an Orbital Angular Momentum Sorter in a Transmission Electron Microscope Using a Convolutional Neural Network. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2022; 29:1-9. [PMID: 36082682 DOI: 10.1017/s143192762201248x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
We report on the automatic alignment of a transmission electron microscope equipped with an orbital angular momentum sorter using a convolutional neural network. The neural network is able to control all relevant parameters of both the electron-optical setup of the microscope and the external voltage source of the sorter without input from the user. It can compensate for mechanical and optical misalignments of the sorter, in order to optimize its spectral resolution. The alignment is completed over a few frames and can be kept stable by making use of the fast fitting time of the neural network.
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Affiliation(s)
- Paolo Rosi
- Istituto Nanoscienze - CNR, via G. Campi 213/A, Modena 41125, Italy
- FIM Department, University of Modena and Reggio Emilia, via G. Campi 213/A, Modena 41125, Italy
| | - Alexander Clausen
- Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons, Forschungszentrum Jülich, Jülich 52425, Germany
| | - Dieter Weber
- Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons, Forschungszentrum Jülich, Jülich 52425, Germany
| | - Amir H Tavabi
- Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons, Forschungszentrum Jülich, Jülich 52425, Germany
| | - Stefano Frabboni
- Istituto Nanoscienze - CNR, via G. Campi 213/A, Modena 41125, Italy
- FIM Department, University of Modena and Reggio Emilia, via G. Campi 213/A, Modena 41125, Italy
| | - Peter Tiemeijer
- Thermo Fisher Scientific, PO Box 80066, 5600 KA Eindhoven, The Netherlands
| | - Rafal E Dunin-Borkowski
- Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons, Forschungszentrum Jülich, Jülich 52425, Germany
| | - Enzo Rotunno
- Istituto Nanoscienze - CNR, via G. Campi 213/A, Modena 41125, Italy
| | - Vincenzo Grillo
- Istituto Nanoscienze - CNR, via G. Campi 213/A, Modena 41125, Italy
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11
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Maxwell AS, Madsen LB, Lewenstein M. Entanglement of orbital angular momentum in non-sequential double ionization. Nat Commun 2022; 13:4706. [PMID: 35948552 PMCID: PMC9365801 DOI: 10.1038/s41467-022-32128-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Accepted: 07/19/2022] [Indexed: 11/30/2022] Open
Abstract
Entanglement has a capacity to enhance imaging procedures, but this remains unexplored for attosecond imaging. Here, we elucidate that possibility, addressing orbital angular momentum (OAM) entanglement in ultrafast processes. In the correlated process non-sequential double ionization (NSDI) we demonstrate robust photoelectron entanglement. In contrast to commonly considered continuous variables, the discrete OAM allows for a simpler interpretation, computation, and measurement of entanglement. The logarithmic negativity reveals that the entanglement is robust to incoherence and an entanglement witness minimizes the number of measurements to detect the entanglement, both quantities are related to OAM coherence terms. We quantify the entanglement for a range of targets and field parameters to find the most entangled photoelectron pairs. This methodology provides a general way to use OAM to quantify and measure entanglement, well-suited to attosecond processes, and can be exploited to enhance imaging capabilities through correlated measurements, or for generation of OAM-entangled electrons. In strong field ionization, entanglement between an electron and an ion has been discussed previously. Here the authors explore orbital angular momentum entanglement between the electrons released in non-sequential double ionization.
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Affiliation(s)
- Andrew S Maxwell
- ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Av. Carl Friedrich Gauss 3, 08860, Castelldefels, Barcelona, Spain. .,Department of Physics and Astronomy, Aarhus University, DK-8000, Aarhus C, Denmark.
| | - Lars Bojer Madsen
- Department of Physics and Astronomy, Aarhus University, DK-8000, Aarhus C, Denmark
| | - Maciej Lewenstein
- ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, Av. Carl Friedrich Gauss 3, 08860, Castelldefels, Barcelona, Spain.,ICREA, Pg. Lluís Companys 23, 08010, Barcelona, Spain
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12
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Johnson CW, Turner AE, García de Abajo FJ, McMorran BJ. Inelastic Mach-Zehnder Interferometry with Free Electrons. PHYSICAL REVIEW LETTERS 2022; 128:147401. [PMID: 35476465 DOI: 10.1103/physrevlett.128.147401] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2021] [Accepted: 03/09/2022] [Indexed: 05/27/2023]
Abstract
We use a novel scanning electron Mach-Zehnder interferometer constructed in a conventional transmission electron microscope to perform inelastic interferometric imaging with free electrons. An electron wave function is prepared in two paths that pass on opposite sides of a gold nanoparticle, where plasmons are excited before the paths are recombined to produce electron interference. We show that the measured spectra are consistent with theoretical predictions, specifically that the interference signal formed by inelastically scattered electrons is π out of phase with respect to that formed by elastically scattered electrons. This technique is sensitive to the phase of localized optical modes, because the interference signal amounts to a substantial fraction of the transmitted electrons. Thus, we argue that inelastic interferometric imaging with our scanning electron Mach-Zehnder interferometer provides a new platform for controlling the transverse momentum of free electrons and studying coherent electron-matter interactions at the nanoscale.
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Affiliation(s)
- Cameron W Johnson
- Department of Physics, University of Oregon, Eugene, Oregon 97403, USA
| | - Amy E Turner
- Department of Physics, University of Oregon, Eugene, Oregon 97403, USA
| | - F Javier García de Abajo
- ICFO-Institut de Ciencies Fotoniques, Mediterranean Technology Park, 08860 Castelldefels (Barcelona), Spain
- ICREA-Institució Catalana de Recerca i Estudis Avançats, Passeig Lluís Companys 23, 08010 Barcelona, Spain
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13
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Bugnet M, Ederer M, Lazarov VK, Li L, Ramasse QM, Löffler S, Kepaptsoglou DM. Imaging the Spatial Distribution of Electronic States in Graphene Using Electron Energy-Loss Spectroscopy: Prospect of Orbital Mapping. PHYSICAL REVIEW LETTERS 2022; 128:116401. [PMID: 35363018 DOI: 10.1103/physrevlett.128.116401] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Revised: 12/23/2021] [Accepted: 01/25/2022] [Indexed: 06/14/2023]
Abstract
The spatial distributions of antibonding π^{*} and σ^{*} states in epitaxial graphene multilayers are mapped using electron energy-loss spectroscopy in a scanning transmission electron microscope. Inelastic channeling simulations validate the interpretation of the spatially resolved signals in terms of electronic orbitals, and demonstrate the crucial effect of the material thickness on the experimental capability to resolve the distribution of unoccupied states. This work illustrates the current potential of core-level electron energy-loss spectroscopy towards the direct visualization of electronic orbitals in a wide range of materials, of huge interest to better understand chemical bonding among many other properties at interfaces and defects in solids.
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Affiliation(s)
- M Bugnet
- SuperSTEM Laboratory, SciTech Daresbury Campus, Daresbury WA4 4AD, United Kingdom
- School of Chemical and Process Engineering, University of Leeds, Leeds LS2 9JT, United Kingdom
- Univ Lyon, CNRS, INSA Lyon, UCBL, MATEIS, UMR 5510, 69621 Villeurbanne, France
| | - M Ederer
- University Service Centre for Transmission Electron Microscopy, TU Wien, Wiedner Hauptstraße 8-10/E057-02, 1040 Wien, Austria
| | - V K Lazarov
- Department of Physics, University of York, York YO10 5DD, United Kingdom
| | - L Li
- Department of Physics and Astronomy, University of West Virginia, Morgantown, West Virginia 26506, USA
| | - Q M Ramasse
- SuperSTEM Laboratory, SciTech Daresbury Campus, Daresbury WA4 4AD, United Kingdom
- School of Chemical and Process Engineering, University of Leeds, Leeds LS2 9JT, United Kingdom
- School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - S Löffler
- University Service Centre for Transmission Electron Microscopy, TU Wien, Wiedner Hauptstraße 8-10/E057-02, 1040 Wien, Austria
| | - D M Kepaptsoglou
- SuperSTEM Laboratory, SciTech Daresbury Campus, Daresbury WA4 4AD, United Kingdom
- Department of Physics, University of York, York YO10 5DD, United Kingdom
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14
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Liang B, Shen F, Wang SM, Zhou Y, Yang Y, Cheng K, Zhang G, Zheng Y, Liu QH, Gong Y. Reconstruction of three-dimensional objects in layered composite structures from multimode orbital angular momentum. Phys Rev E 2022; 105:025302. [PMID: 35291077 DOI: 10.1103/physreve.105.025302] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Accepted: 01/13/2022] [Indexed: 06/14/2023]
Abstract
Because of helical phase wavefront distribution, vortex electromagnetic waves are considered to carry more information and additional degrees of freedom than traditional spherical waves. Therefore, a vortex wave carrying orbital angular momentum (OAM) can improve inversion and imaging accuracy. In this work, we revisit the reconstruction of three-dimensional objects in layered composite structures extended with OAM. In forward modeling, the concentric uniform circle array is used to generate electromagnetic vortex beams. To analyze the difference of vortex beams, the electric field radiation pattern and phase pattern distribution of OAM waves with different modes are calculated. Then, the scattered field of layered media illuminated by different OAM beams is determined by the dyadic Green's function and the stabilized biconjugate gradient technique with a fast Fourier transform algorithm. In the inversion, the variational Born iterative method is used to reconstruct targets in layered composite structures, and multiple OAM modes are used to improve the reconstruction results. The numerical results prove that the permittivity of the target can be better reconstructed by using the multiple OAM modes rather than the traditional spherical wave. With the increase of OAM mode number, the reconstructed target parameters are closer to the true value. We expect that our results will provide a better understanding of the OAM and pave the way for the improvement of inversion and optical imaging technology using vortex waves.
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Affiliation(s)
- Bingyang Liang
- International School of Microelectronics, Dongguan University of Technology, Dongguan 523808, China
- National Key Laboratory on Vacuum Electronics, University of Electronic Science and Technology of China (UESTC), Chengdu 610054, China
| | - Fei Shen
- International School of Microelectronics, Dongguan University of Technology, Dongguan 523808, China
| | - Shao Meng Wang
- National Key Laboratory on Vacuum Electronics, University of Electronic Science and Technology of China (UESTC), Chengdu 610054, China
| | - Yuanguo Zhou
- College of Communication and Information Engineering, Xi'an University of Science and Technology, Xi'an 710054, China
| | - Yang Yang
- International School of Microelectronics, Dongguan University of Technology, Dongguan 523808, China
| | - Kaiyang Cheng
- International School of Microelectronics, Dongguan University of Technology, Dongguan 523808, China
| | - Guangmin Zhang
- School of Environment and Civil Engineering, Dongguan University of Technology, Dongguan 523808, China
| | - Yu Zheng
- School of Environment and Civil Engineering, Dongguan University of Technology, Dongguan 523808, China
| | - Qing Huo Liu
- Department of Electrical and Computer Engineering, Duke University, Durham, North Carolina 27708, USA
| | - Yubin Gong
- International School of Microelectronics, Dongguan University of Technology, Dongguan 523808, China
- National Key Laboratory on Vacuum Electronics, University of Electronic Science and Technology of China (UESTC), Chengdu 610054, China
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15
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Roitman D, Shiloh R, Lu PH, Dunin-Borkowski RE, Arie A. Shaping of Electron Beams Using Sculpted Thin Films. ACS PHOTONICS 2021; 8:3394-3405. [PMID: 34938823 PMCID: PMC8679091 DOI: 10.1021/acsphotonics.1c00951] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Revised: 10/31/2021] [Accepted: 11/04/2021] [Indexed: 05/04/2023]
Abstract
Electron beam shaping by sculpted thin films relies on electron-matter interactions and the wave nature of electrons. It can be used to study physical phenomena of special electron beams and to develop technological applications in electron microscopy that offer new and improved measurement techniques and increased resolution in different imaging modes. In this Perspective, we review recent applications of sculpted thin films for electron orbital angular momentum sorting, improvements in phase contrast transmission electron microscopy, and aberration correction. For the latter, we also present new results of our work toward correction of the spherical aberration of Lorentz scanning transmission electron microscopes and suggest a method to correct chromatic aberration using thin films. This review provides practical insight for researchers in the field and motivates future progress in electron microscopy.
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Affiliation(s)
- Dolev Roitman
- School
of Electrical Engineering, Fleischman Faculty of Engineering, Tel Aviv University, Tel Aviv 69978, Israel
| | - Roy Shiloh
- Physics
Department, Friedrich-Alexander-Universität
Erlangen-Nürnberg, Erlangen 91058, Germany
| | - Peng-Han Lu
- Ernst
Ruska-Centre for Microscopy and Spectroscopy with Electrons and Peter
Grünberg Institute, Forschungszentrum
Jülich, Jülich 52428, Germany
- RWTH
Aachen University, Aachen 52062, Germany
| | - Rafal E. Dunin-Borkowski
- Ernst
Ruska-Centre for Microscopy and Spectroscopy with Electrons and Peter
Grünberg Institute, Forschungszentrum
Jülich, Jülich 52428, Germany
| | - Ady Arie
- School
of Electrical Engineering, Fleischman Faculty of Engineering, Tel Aviv University, Tel Aviv 69978, Israel
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16
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Schachinger T, Hartel P, Lu PH, Löffler S, Obermair M, Dries M, Gerthsen D, Dunin-Borkowski RE, Schattschneider P. Experimental realization of a π/2 vortex mode converter for electrons using a spherical aberration corrector. Ultramicroscopy 2021; 229:113340. [PMID: 34311124 DOI: 10.1016/j.ultramic.2021.113340] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Revised: 05/18/2021] [Accepted: 06/10/2021] [Indexed: 10/21/2022]
Abstract
In light optics, beams with orbital angular momentum (OAM) can be produced by employing a properly-tuned two-cylinder-lens arrangement, also called π/2 mode converter. It is not possible to convey this concept directly to the beam in an electron microscope due to the non-existence of cylinder lenses in commercial transmission electron microscopes (TEMs). A viable work-around are readily-available electron optical elements in the form of quadrupole lenses. In a proof-of-principle experiment in 2012, it has been shown that a single quadrupole in combination with a Hilbert phase-plate produces a spatially-confined, transient vortex mode. Here, an analogue to an optical π/2 mode converter is realized by repurposing a CEOS DCOR probe corrector in an aberration corrected TEM in a way that it resembles a dual cylinder lens using two quadrupoles. In order to verify the presence of OAM in the output beam, a fork dislocation grating is used as an OAM analyser. The possibility to use magnetic quadrupole fields instead of, e.g., prefabricated fork dislocation gratings to produce electron beams carrying OAM enhances the beam brightness by almost an order of magnitude and delivers switchable high-mode purity vortex beams without unwanted side-bands.
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Affiliation(s)
- T Schachinger
- Institute of Solid State Physics, TU Wien, Wiedner Hauptstraße 8-10, 1040 Wien, Austria; University Service Centre for Transmission Electron Microscopy (USTEM), TU Wien, Wiedner Hauptstraße 8-10, 1040 Wien, Austria.
| | - P Hartel
- CEOS Corrected Electron Optical Systems GmbH, Englerstraße 28, 69126 Heidelberg, Germany
| | - P-H Lu
- Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons (ER-C) and Peter Grünberg Institute, Forschungszentrum Jülich, 52425 Jülich, Germany; RWTH Aachen University, Ahornstraße 55, 52074 Aachen, Germany
| | - S Löffler
- University Service Centre for Transmission Electron Microscopy (USTEM), TU Wien, Wiedner Hauptstraße 8-10, 1040 Wien, Austria
| | - M Obermair
- Laboratorium für Elektronenmikroskopie (LEM), Karlsruher Institut für Technologie (KIT), Engesserstraße 7, 76131 Karlsruhe, Germany
| | - M Dries
- Laboratorium für Elektronenmikroskopie (LEM), Karlsruher Institut für Technologie (KIT), Engesserstraße 7, 76131 Karlsruhe, Germany
| | - D Gerthsen
- Laboratorium für Elektronenmikroskopie (LEM), Karlsruher Institut für Technologie (KIT), Engesserstraße 7, 76131 Karlsruhe, Germany
| | - R E Dunin-Borkowski
- Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons (ER-C) and Peter Grünberg Institute, Forschungszentrum Jülich, 52425 Jülich, Germany
| | - P Schattschneider
- Institute of Solid State Physics, TU Wien, Wiedner Hauptstraße 8-10, 1040 Wien, Austria; University Service Centre for Transmission Electron Microscopy (USTEM), TU Wien, Wiedner Hauptstraße 8-10, 1040 Wien, Austria
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17
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Luski A, Segev Y, David R, Bitton O, Nadler H, Barnea AR, Gorlach A, Cheshnovsky O, Kaminer I, Narevicius E. Vortex beams of atoms and molecules. Science 2021; 373:1105-1109. [PMID: 34516841 DOI: 10.1126/science.abj2451] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
[Figure: see text].
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Affiliation(s)
- Alon Luski
- Faculty of Chemistry, Weizmann Institute of Science, Rehovot, Israel
| | - Yair Segev
- Faculty of Chemistry, Weizmann Institute of Science, Rehovot, Israel
| | - Rea David
- Faculty of Chemistry, Weizmann Institute of Science, Rehovot, Israel
| | - Ora Bitton
- Faculty of Chemistry, Weizmann Institute of Science, Rehovot, Israel
| | - Hila Nadler
- Faculty of Chemistry, Weizmann Institute of Science, Rehovot, Israel
| | - A Ronny Barnea
- School of Chemistry, Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Alexey Gorlach
- Department of Electrical and Computer Engineering, Technion - Israel Institute of Technology, Haifa, Israel
| | - Ori Cheshnovsky
- School of Chemistry, Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Ido Kaminer
- Department of Electrical and Computer Engineering, Technion - Israel Institute of Technology, Haifa, Israel
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18
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Zhang Y, Lu PH, Rotunno E, Troiani F, van Schayck JP, Tavabi AH, Dunin-Borkowski RE, Grillo V, Peters PJ, Ravelli RBG. Single-particle cryo-EM: alternative schemes to improve dose efficiency. JOURNAL OF SYNCHROTRON RADIATION 2021; 28:1343-1356. [PMID: 34475283 PMCID: PMC8415325 DOI: 10.1107/s1600577521007931] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Accepted: 08/02/2021] [Indexed: 06/13/2023]
Abstract
Imaging of biomolecules by ionizing radiation, such as electrons, causes radiation damage which introduces structural and compositional changes of the specimen. The total number of high-energy electrons per surface area that can be used for imaging in cryogenic electron microscopy (cryo-EM) is severely restricted due to radiation damage, resulting in low signal-to-noise ratios (SNR). High resolution details are dampened by the transfer function of the microscope and detector, and are the first to be lost as radiation damage alters the individual molecules which are presumed to be identical during averaging. As a consequence, radiation damage puts a limit on the particle size and sample heterogeneity with which electron microscopy (EM) can deal. Since a transmission EM (TEM) image is formed from the scattering process of the electron by the specimen interaction potential, radiation damage is inevitable. However, we can aim to maximize the information transfer for a given dose and increase the SNR by finding alternatives to the conventional phase-contrast cryo-EM techniques. Here some alternative transmission electron microscopy techniques are reviewed, including phase plate, multi-pass transmission electron microscopy, off-axis holography, ptychography and a quantum sorter. Their prospects for providing more or complementary structural information within the limited lifetime of the sample are discussed.
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Affiliation(s)
- Yue Zhang
- Maastricht Multimodal Molecular Imaging Institute, Division of Nanoscopy, Maastricht University, Universiteitssingel 50, Maastricht 6229 ER, The Netherlands
| | - Peng-Han Lu
- Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons and Peter Grünberg Institute, Forschungszentrum Jülich, Jülich 52425, Germany
| | - Enzo Rotunno
- CNR-Istituto Nanoscienze, Centro S3, Via G Campi 213/A, I-41125 Modena, Italy
| | - Filippo Troiani
- CNR-Istituto Nanoscienze, Centro S3, Via G Campi 213/A, I-41125 Modena, Italy
| | - J. Paul van Schayck
- Maastricht Multimodal Molecular Imaging Institute, Division of Nanoscopy, Maastricht University, Universiteitssingel 50, Maastricht 6229 ER, The Netherlands
| | - Amir H. Tavabi
- Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons and Peter Grünberg Institute, Forschungszentrum Jülich, Jülich 52425, Germany
| | - Rafal E. Dunin-Borkowski
- Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons and Peter Grünberg Institute, Forschungszentrum Jülich, Jülich 52425, Germany
| | - Vincenzo Grillo
- CNR-Istituto Nanoscienze, Centro S3, Via G Campi 213/A, I-41125 Modena, Italy
| | - Peter J. Peters
- Maastricht Multimodal Molecular Imaging Institute, Division of Nanoscopy, Maastricht University, Universiteitssingel 50, Maastricht 6229 ER, The Netherlands
| | - Raimond B. G. Ravelli
- Maastricht Multimodal Molecular Imaging Institute, Division of Nanoscopy, Maastricht University, Universiteitssingel 50, Maastricht 6229 ER, The Netherlands
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19
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Alignment of electron optical beam shaping elements using a convolutional neural network. Ultramicroscopy 2021; 228:113338. [PMID: 34218137 DOI: 10.1016/j.ultramic.2021.113338] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 05/28/2021] [Accepted: 06/09/2021] [Indexed: 11/23/2022]
Abstract
A convolutional neural network is used to align an orbital angular momentum sorter in a transmission electron microscope. The method is demonstrated using simulations and experiments. As a result of its accuracy and speed, it offers the possibility of real-time tuning of other electron optical devices and electron beam shaping configurations.
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20
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Pozzi G, Rosi P, Tavabi AH, Karimi E, Dunin-Borkowski RE, Grillo V. A sorter for electrons based on magnetic elements. Ultramicroscopy 2021; 231:113287. [PMID: 33926773 DOI: 10.1016/j.ultramic.2021.113287] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Revised: 04/01/2021] [Accepted: 04/10/2021] [Indexed: 10/21/2022]
Abstract
The orbital angular momentum (OAM) sorter is an electron optical device for the measurement of an electron's OAM. It is based on two phase elements, which are referred to as an "unwrapper" and a "corrector" and are located in Fourier conjugate planes. The simplest implementation of the sorter is based on electrostatic phase elements, such as a charged needle for the unwrapper and electrodes with alternating charges or potentials for the corrector. Here, we use a formal analogy between phase shifts introduced by charges and vertical currents to propose alternative designs for the sorter elements, which are based on phase shifts introduced by magnetic fields. We use this concept to provide a general guide for phase element design, which promises to provide improved reliability of phase control in electron optics.
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Affiliation(s)
- Giulio Pozzi
- Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons and Peter Grünberg Institute, Forschungszentrum Jülich, 52425 Jülich, Germany; Department of Physics and Astronomy, University of Bologna, viale B. Pichat 6/2, 40127 Bologna, Italy
| | - Paolo Rosi
- Department FIM, University of Modena and Reggio Emilia, via G. Campi 213/a, 41125 Modena, Italy
| | - Amir H Tavabi
- Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons and Peter Grünberg Institute, Forschungszentrum Jülich, 52425 Jülich, Germany.
| | - Ebrahim Karimi
- Department of Physics, University of Ottawa, 25 Templeton Street, Ottawa, Ontario K1N 6N5, Canada
| | - Rafal E Dunin-Borkowski
- Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons and Peter Grünberg Institute, Forschungszentrum Jülich, 52425 Jülich, Germany
| | - Vincenzo Grillo
- Department FIM, University of Modena and Reggio Emilia, via G. Campi 213/a, 41125 Modena, Italy; CNR-Institute of Nanoscience-S3, via G. Campi 213/a, 41125 Modena, Italy.
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21
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Guido CA, Rotunno E, Zanfrognini M, Corni S, Grillo V. Exploring the Spatial Features of Electronic Transitions in Molecular and Biomolecular Systems by Swift Electrons. J Chem Theory Comput 2021; 17:2364-2373. [PMID: 33646769 PMCID: PMC8047794 DOI: 10.1021/acs.jctc.1c00045] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
![]()
We
devise a new kind of experiment that extends the technology
of electron energy loss spectroscopy to probe (supra-)molecular systems: by using
an electron beam in a configuration that avoids
molecular damage and a very recently introduced electron optics setup
for the analysis of the outcoming electrons, one can obtain information
on the spatial features of the investigated excitations. Physical
insight into the proposed experiment is provided by means of a simple
but rigorous model to obtain the transition rate and selection rule.
Numerical simulations of DNA G-quadruplexes and other biomolecular
systems, based on time dependent density functional theory calculations,
point out that the conceived new technique can probe the multipolar
components and even the chirality of molecular transitions, superseding
the usual optical spectroscopies for those cases that are problematic,
such as dipole-forbidden transitions, at a very high spatial resolution.
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Affiliation(s)
- Ciro A Guido
- Dipartimento di Scienze Chimiche, Università di Padova, via F. Marzolo 1, 35131 Padova, Italy
| | - Enzo Rotunno
- CNR-NANO, Institute of Nanoscience, via Campi 213/A, Modena, Italy
| | | | - Stefano Corni
- Dipartimento di Scienze Chimiche, Università di Padova, via F. Marzolo 1, 35131 Padova, Italy.,CNR-NANO, Institute of Nanoscience, via Campi 213/A, Modena, Italy
| | - Vincenzo Grillo
- CNR-NANO, Institute of Nanoscience, via Campi 213/A, Modena, Italy
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