Ropers, Claus

[["dc.contributor.author","Feist, Armin"],["dc.contributor.author","Yalunin, Sergey Valerevich"],["dc.contributor.author","Schäfer, Sascha"],["dc.contributor.author","Ropers, Claus"],["dc.date.accessioned","2020-05-29T09:51:23Z"],["dc.date.available","2020-05-29T09:51:23Z"],["dc.date.issued","2020"],["dc.identifier.arxiv","2003.01938"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/66023"],["dc.title","High-purity free-electron momentum states prepared by three-dimensional optical phase modulation"],["dc.type","preprint"],["dc.type.internalPublication","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","08012"],["dc.contributor.author","Feist, Armin"],["dc.contributor.author","Priebe, Katharina E."],["dc.contributor.author","Rathje, Christopher"],["dc.contributor.author","Bach, Nora"],["dc.contributor.author","Rubiano da Silva, Nara"],["dc.contributor.author","Danz, Thomas"],["dc.contributor.author","Möller, Marcel"],["dc.contributor.author","Domröse, Till"],["dc.contributor.author","Rittmann, Thomas"],["dc.contributor.author","Yalunin, Sergey Valerevich"],["dc.contributor.author","Hohage, Thorsten"],["dc.contributor.author","Sivis, Murat"],["dc.contributor.author","Schäfer, Sascha"],["dc.contributor.author","Ropers, Claus"],["dc.date.accessioned","2020-05-15T12:39:40Z"],["dc.date.available","2020-05-15T12:39:40Z"],["dc.date.issued","2019"],["dc.identifier.doi","10.1051/epjconf/201920508012"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/65455"],["dc.relation.conference","XXI International Conference on Ultrafast Phenomena 2018 (UP 2018)"],["dc.relation.eventend","2018-07-20"],["dc.relation.eventlocation","Hamburg"],["dc.relation.eventstart","2018-07-15"],["dc.relation.ispartof","XXI International Conference on Ultrafast Phenomena 2018 (UP 2018)"],["dc.title","Generation and attosecond shaping of high coherence free-electron beams for ultrafast TEM"],["dc.type","conference_paper"],["dc.type.internalPublication","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","504"],["dc.bibliographiccitation.issue","7"],["dc.bibliographiccitation.journal","MRS Bulletin"],["dc.bibliographiccitation.lastpage","511"],["dc.bibliographiccitation.volume","43"],["dc.contributor.author","Feist, Armin"],["dc.contributor.author","Storeck, Gero"],["dc.contributor.author","Schäfer, Sascha"],["dc.contributor.author","Ropers, Claus"],["dc.date.accessioned","2019-11-15T11:06:07Z"],["dc.date.available","2019-11-15T11:06:07Z"],["dc.date.issued","2018"],["dc.description.abstract","Ultrafast measurement technology provides essential contributions to our understanding of the properties and functions of solids and nanostructures. Atomic-scale vistas with ever-growing spatial and temporal resolution are offered by methods based on short pulses of x-rays and electrons. Time-resolved electron diffraction and microscopy are among the most powerful approaches to investigate nonequilibrium structural dynamics. In this article, we discuss recent advances in ultrafast electron imaging enabled by significant improvements in the coherence of pulsed electron beams. Specifically, we review the development and first application of ultrafast low-energy electron diffraction for the study of structural dynamics at surfaces, and discuss novel opportunities for ultrafast transmission electron microscopy facilitated by laser-triggered field-emission sources. These and further developments will render coherent electron beams an essential component in future ultrafast nanoscale imaging. Introduction."],["dc.identifier.doi","10.1557/mrs.2018.153"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/62633"],["dc.language.iso","en"],["dc.relation.issn","0883-7694"],["dc.relation.issn","1938-1425"],["dc.title","Structural dynamics probed by high-coherence electron pulses"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","200"],["dc.bibliographiccitation.issue","7551"],["dc.bibliographiccitation.journal","Nature"],["dc.bibliographiccitation.lastpage","+"],["dc.bibliographiccitation.volume","521"],["dc.contributor.author","Feist, Armin"],["dc.contributor.author","Echternkamp, Katharina E."],["dc.contributor.author","Schauss, Jakob"],["dc.contributor.author","Yalunin, Sergey V."],["dc.contributor.author","Schäfer, Sascha"],["dc.contributor.author","Ropers, Claus"],["dc.date.accessioned","2018-11-07T09:57:15Z"],["dc.date.available","2018-11-07T09:57:15Z"],["dc.date.issued","2015"],["dc.description.abstract","Coherent manipulation of quantum systems with light is expected to be a cornerstone of future information and communication technology, including quantum computation and cryptography(1). The transfer of an optical phase onto a quantum wavefunction is a defining aspect of coherent interactions and forms the basis of quantum state preparation, synchronization and metrology. Light-phase-modulated electron states near atoms and molecules are essential for the techniques of attosecond science, including the generation of extreme-ultraviolet pulses and orbital tomography(2,3). In contrast, the quantum-coherent phase-modulation of energetic free-electron beams has not been demonstrated, although it promises direct access to ultrafast imaging and spectroscopy with tailored electron pulses on the attosecond scale. Here we demonstrate the coherent quantum state manipulation of free-electron populations in an electron microscope beam. We employ the interaction of ultrashort electron pulses with optical nearfields(4-9) to induce Rabi oscillations in the populations of electron momentum states, observed as a function of the optical driving field. Excellent agreement with the scaling of an equal-Rabi multi-level quantum ladder is obtained(10), representing the observation of a light-driven 'quantum walk'(5) coherently reshaping electron density in momentum space(11). We note that, after the interaction, the optically generated superposition of momentum states evolves into a train of attosecond electron pulses. Our results reveal the potential of quantum control for the precision structuring of electron densities, with possible applications ranging from ultrafast electron spectroscopy and microscopy to accelerator science and free-electron lasers."],["dc.identifier.doi","10.1038/nature14463"],["dc.identifier.isi","000354377800054"],["dc.identifier.pmid","25971512"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/37119"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.relation","SFB 1073: Kontrolle von Energiewandlung auf atomaren Skalen"],["dc.relation","SFB 1073 | Topical Area A | A05 Nanoskalige Untersuchung raumzeitlicher Relaxation in heterogenen Systemen mit ultraschneller Transmissionselektronenmikroskopie"],["dc.relation.issn","1476-4687"],["dc.relation.issn","0028-0836"],["dc.title","Quantum coherent optical phase modulation in an ultrafast transmission electron microscope"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.subtype","original_ja"],["dspace.entity.type","Publication"]]

[["dc.contributor.author","Henke, Jan-Wilke"],["dc.contributor.author","Raja, Arslan Sajid"],["dc.contributor.author","Feist, Armin"],["dc.contributor.author","Huang, Guanhao"],["dc.contributor.author","Arend, Germaine"],["dc.contributor.author","Yang, Yujia"],["dc.contributor.author","Kappert, F. Jasmin"],["dc.contributor.author","Wang, Rui Ning"],["dc.contributor.author","Möller, Marcel"],["dc.contributor.author","Pan, Jiahe"],["dc.contributor.author","Liu, Junqiu"],["dc.contributor.author","Kfir, Ofer"],["dc.contributor.author","Ropers, Claus"],["dc.contributor.author","Kippenberg, Tobias J."],["dc.date.accessioned","2021-11-17T18:38:51Z"],["dc.date.available","2021-11-17T18:38:51Z"],["dc.date.issued","2021-05-08"],["dc.description.abstract","The ability to tailor laser light on a chip using integrated photonics has allowed for extensive control over fundamental light-matter interactions in manifold quantum systems including atoms, trapped ions, quantum dots, and defect centers. Free electrons, enabling high-resolution microscopy for decades, are increasingly becoming the subject of laser-based quantum manipulation. Using free-space optical excitation and intense laser pulses, this has led to the observation of free-electron quantum walks, attosecond electron pulses, and imaging of electromagnetic fields. Enhancing the interaction with electron beams through chip-based photonics promises unique applications in nanoscale quantum control and sensing, but has yet to enter electron microscopy. Here, we merge integrated photonics with electron microscopy, demonstrating coherent phase modulation of an electron beam using a silicon nitride microresonator driven by a continuous-wave laser. The high-Q factor (~0^6$) cavity enhancement and a waveguide designed for phase matching lead to efficient electron-light scattering at unprecedentedly low, few-microwatt optical powers. Specifically, we fully deplete the initial electron state at a cavity-coupled power of 6 $\\mu and create >500 photon sidebands for only 38 mW in the bus waveguide. Moreover, we demonstrate $\\mu electron energy gain spectroscopy (EEGS). Providing simultaneous optical and electronic spectroscopy of the resonant cavity, the fiber-coupled photonic structures feature single-mode electron-light interaction with full control over the input and output channels. This approach establishes a versatile framework for exploring free-electron quantum optics, with future developments in strong coupling, local quantum probing, and electron-photon entanglement. Our results highlight the potential of integrated photonics to efficiently interface free electrons and light."],["dc.identifier.arxiv","2105.03729"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/93174"],["dc.relation","SFB 1456: Mathematik des Experiments: Die Herausforderung indirekter Messungen in den Naturwissenschaften"],["dc.relation","SFB 1456 | Cluster C: Data with Information in Their Dependency Structure"],["dc.relation","SFB 1456 | Cluster C | C01: Density matrix reconstructions in ultrafast free electron optics"],["dc.relation.orgunit","Max-Planck-Institut für biophysikalische Chemie"],["dc.relation.orgunit","IV. Physikalisches Institut"],["dc.title","Integrated photonics enables continuous-beam electron phase modulation"],["dc.type","preprint"],["dc.type.internalPublication","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","1720"],["dc.bibliographiccitation.issue","S2"],["dc.bibliographiccitation.journal","Microscopy and Microanalysis"],["dc.bibliographiccitation.lastpage","1721"],["dc.bibliographiccitation.volume","25"],["dc.contributor.author","Harvey, Tyler"],["dc.contributor.author","Henke, Jan-Wilke"],["dc.contributor.author","Kfir, Ofer"],["dc.contributor.author","Feist, Armin"],["dc.contributor.author","Ropers, Claus"],["dc.date.accessioned","2020-06-02T09:25:23Z"],["dc.date.available","2020-06-02T09:25:23Z"],["dc.date.issued","2019"],["dc.identifier.doi","10.1017/S1431927619009334"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/66036"],["dc.relation.issn","1431-9276"],["dc.relation.issn","1435-8115"],["dc.title","Imaging Chiral Materials with Photon-Induced Near-Field Electron Microscopy"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","1000"],["dc.bibliographiccitation.issue","11"],["dc.bibliographiccitation.journal","Nature Physics"],["dc.bibliographiccitation.lastpage","1004"],["dc.bibliographiccitation.volume","12"],["dc.contributor.author","Echternkamp, Katharina E."],["dc.contributor.author","Feist, Armin"],["dc.contributor.author","Schäfer, Sascha"],["dc.contributor.author","Ropers, Claus"],["dc.date.accessioned","2020-12-10T18:09:32Z"],["dc.date.available","2020-12-10T18:09:32Z"],["dc.date.issued","2016"],["dc.description.abstract","Quantum coherent evolution, interference between multiple distinct paths(1-4) and phase-controlled sequential interactions are the basis for powerful multi-dimensional optical(5) and nuclear magnetic resonance(3) spectroscopies, including Ramsey's method of separated fields(6). Recent developments in the quantum state preparation of free electrons(7) suggest a transfer of such concepts to ultrafast electron imaging and spectroscopy. Here, we demonstrate the sequential coherent manipulation of free-electron superposition states in an ultrashort electron pulse, using nanostructures featuring two spatially separated near-fields with polarization anisotropy. The incident light polarization controls the relative phase of these near-fields, yielding constructive and destructive quantum interference of the subsequent interactions. Future implementations of such electron-light interferometers may provide access to optically phase-resolved electronic dynamics and dephasing mechanisms with attosecond precision."],["dc.identifier.doi","10.1038/nphys3844"],["dc.identifier.eissn","1745-2481"],["dc.identifier.isi","000387245700009"],["dc.identifier.issn","1745-2473"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/73685"],["dc.identifier.url","https://publications.goettingen-research-online.de/handle/2/39101"],["dc.language.iso","en"],["dc.notes.intern","DOI Import GROB-354"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.relation","SFB 1073: Kontrolle von Energiewandlung auf atomaren Skalen"],["dc.relation","SFB 1073 | Topical Area A | A05 Nanoskalige Untersuchung raumzeitlicher Relaxation in heterogenen Systemen mit ultraschneller Transmissionselektronenmikroskopie"],["dc.relation.issn","1745-2481"],["dc.relation.issn","1745-2473"],["dc.title","Ramsey-type phase control of free-electron beams"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.subtype","original_ja"],["dspace.entity.type","Publication"]]

[["dc.contributor.author","Feist, Armin"],["dc.contributor.author","Echternkamp, Katharina E."],["dc.contributor.author","Bormann, Reiner"],["dc.contributor.author","Rubiano da Silva, Nara"],["dc.contributor.author","Möller, Marcel"],["dc.contributor.author","Liang, Wenxi"],["dc.contributor.author","Schäfer, Sascha"],["dc.contributor.author","Ropers, Claus"],["dc.date.accessioned","2020-02-03T09:17:06Z"],["dc.date.available","2020-02-03T09:17:06Z"],["dc.date.issued","2016"],["dc.description.abstract","We demonstrate the generation of low-emittance ultrashort electron pulses derived from nanoscale photocathodes and their application in ultrafast transmission electron microscopy. Few-nanometer electron focal spot diameters are achieved, enabling the investigation of ultrafast nanoscale dynamics."],["dc.identifier.doi","10.1364/up.2016.uth2b.5"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/62937"],["dc.language.iso","en"],["dc.publisher","OSA - The Optical Society"],["dc.publisher.place","Washington, D.C."],["dc.relation.conference","International Conference on Ultrafast Phenomena 2016"],["dc.relation.eventend","2016-07-22"],["dc.relation.eventlocation","Santa Fe, New Mexico United States"],["dc.relation.eventstart","2016-07-17"],["dc.relation.isbn","978-1-943580-18-7"],["dc.relation.ispartof","Proceedings of the International Conference on Ultrafast Phenomena 2016"],["dc.title","Few-nanometer femtosecond electron probe pulses in ultrafast transmission electron microscop"],["dc.type","conference_paper"],["dc.type.internalPublication","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","793"],["dc.bibliographiccitation.issue","12"],["dc.bibliographiccitation.journal","Nature Photonics"],["dc.bibliographiccitation.lastpage","797"],["dc.bibliographiccitation.volume","11"],["dc.contributor.author","Priebe, Katharina E."],["dc.contributor.author","Rathje, Christopher"],["dc.contributor.author","Yalunin, Sergey V."],["dc.contributor.author","Hohage, Thorsten"],["dc.contributor.author","Feist, Armin"],["dc.contributor.author","Schäfer, Sascha"],["dc.contributor.author","Ropers, Claus"],["dc.date.accessioned","2019-11-15T11:12:06Z"],["dc.date.available","2019-11-15T11:12:06Z"],["dc.date.issued","2017"],["dc.identifier.arxiv","1706.03680"],["dc.identifier.doi","10.1038/s41566-017-0045-8"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/62634"],["dc.language.iso","en"],["dc.relation","SFB 1073: Kontrolle von Energiewandlung auf atomaren Skalen"],["dc.relation","SFB 1073 | Topical Area A | A05 Nanoskalige Untersuchung raumzeitlicher Relaxation in heterogenen Systemen mit ultraschneller Transmissionselektronenmikroskopie"],["dc.relation.issn","1749-4885"],["dc.relation.issn","1749-4893"],["dc.relation.orgunit","Institut für Numerische und Angewandte Mathematik"],["dc.title","Attosecond electron pulse trains and quantum state reconstruction in ultrafast transmission electron microscopy"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.subtype","original_ja"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","1"],["dc.bibliographiccitation.lastpage","1"],["dc.contributor.author","Feist, Armin"],["dc.contributor.author","Rittmann, Thomas"],["dc.contributor.author","Harvey, Tyler"],["dc.contributor.author","Priebe, Katharina E."],["dc.contributor.author","Rathje, Christopher"],["dc.contributor.author","Kfir, Ofer"],["dc.contributor.author","Henke, Jan-Wilke"],["dc.contributor.author","Yalunin, Sergey Valerevich"],["dc.contributor.author","Schäfer, Sascha"],["dc.contributor.author","Ropers, Claus"],["dc.date.accessioned","2019-11-15T12:40:59Z"],["dc.date.available","2019-11-15T12:40:59Z"],["dc.date.issued","2019"],["dc.identifier.doi","10.1109/CLEOE-EQEC.2019.8872437"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/62636"],["dc.notes.preprint","yes"],["dc.relation.conference","2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC)"],["dc.relation.eventend","2019-06-27"],["dc.relation.eventlocation","München"],["dc.relation.eventstart","2019-06-23"],["dc.relation.isbn","978-1-7281-0469-0"],["dc.relation.iserratumof","yes"],["dc.title","Probing Nanoscale Optical Fields and Phase-Shaping Electron Beams by Inelastic Electron-Light Scattering"],["dc.type","conference_paper"],["dc.type.internalPublication","yes"],["dspace.entity.type","Publication"]]