Feist, Armin

[["dc.bibliographiccitation.firstpage","034301"],["dc.bibliographiccitation.issue","3"],["dc.bibliographiccitation.journal","Structural Dynamics"],["dc.bibliographiccitation.volume","9"],["dc.contributor.author","Bach, N."],["dc.contributor.author","Feist, Armin"],["dc.contributor.author","Möller, M."],["dc.contributor.author","Ropers, C."],["dc.contributor.author","Schäfer, S."],["dc.date.accessioned","2022-08-23T06:36:17Z"],["dc.date.available","2022-08-23T06:36:17Z"],["dc.date.issued","2022-06-03"],["dc.identifier.doi","10.1063/4.0000144"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/113085"],["dc.language.iso","en"],["dc.relation","SFB 1073 | Topical Area A | A05 Nanoskalige Untersuchung raumzeitlicher Relaxation in heterogenen Systemen mit ultraschneller Transmissionselektronenmikroskopie"],["dc.relation.issn","2329-7778"],["dc.relation.orgunit","IV. Physikalisches Institut"],["dc.relation.orgunit","Max-Planck-Institut für Multidisziplinäre Naturwissenschaften"],["dc.rights","CC BY 4.0"],["dc.title","Tailored nanophononic wavefield in a patterned bilayer system probed by ultrafast convergent beam electron diffraction"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.subtype","original_ja"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","Light"],["dc.bibliographiccitation.volume","10"],["dc.contributor.author","Liebtrau, Matthias"],["dc.contributor.author","Sivis, Murat"],["dc.contributor.author","Feist, Armin"],["dc.contributor.author","Lourenço-Martins, Hugo"],["dc.contributor.author","Pazos-Pérez, Nicolas"],["dc.contributor.author","Alvarez-Puebla, Ramon A."],["dc.contributor.author","de Abajo, F. Javier García"],["dc.contributor.author","Polman, Albert"],["dc.contributor.author","Ropers, Claus"],["dc.date.accessioned","2021-06-01T09:41:38Z"],["dc.date.available","2021-06-01T09:41:38Z"],["dc.date.issued","2021"],["dc.description.abstract","The interplay between free electrons, light, and matter offers unique prospects for space, time, and energy resolved optical material characterization, structured light generation, and quantum information processing. Here, we study the nanoscale features of spontaneous and stimulated electron–photon interactions mediated by localized surface plasmon resonances at the tips of a gold nanostar using electron energy-loss spectroscopy (EELS), cathodoluminescence spectroscopy (CL), and photon-induced near-field electron microscopy (PINEM). Supported by numerical electromagnetic boundary-element method (BEM) calculations, we show that the different coupling mechanisms probed by EELS, CL, and PINEM feature the same spatial dependence on the electric field distribution of the tip modes. However, the electron–photon interaction strength is found to vary with the incident electron velocity, as determined by the spatial Fourier transform of the electric near-field component parallel to the electron trajectory. For the tightly confined plasmonic tip resonances, our calculations suggest an optimum coupling velocity at electron energies as low as a few keV. Our results are discussed in the context of more complex geometries supporting multiple modes with spatial and spectral overlap. We provide fundamental insights into spontaneous and stimulated electron-light-matter interactions with key implications for research on (quantum) coherent optical phenomena at the nanoscale."],["dc.identifier.doi","10.1038/s41377-021-00511-y"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/84986"],["dc.language.iso","en"],["dc.notes.intern","DOI-Import GROB-425"],["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.eissn","2047-7538"],["dc.rights","CC BY 4.0"],["dc.title","Spontaneous and stimulated electron–photon interactions in nanoscale plasmonic near fields"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.subtype","original_ja"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","711"],["dc.bibliographiccitation.issue","8"],["dc.bibliographiccitation.journal","MRS Bulletin"],["dc.bibliographiccitation.lastpage","719"],["dc.bibliographiccitation.volume","46"],["dc.contributor.author","Harvey, Tyler R."],["dc.contributor.author","Rubiano da Silva, Nara"],["dc.contributor.author","Gaida, John H."],["dc.contributor.author","Möller, Marcel"],["dc.contributor.author","Feist, Armin"],["dc.contributor.author","Schäfer, Sascha"],["dc.contributor.author","Ropers, Claus"],["dc.date.accessioned","2021-12-01T09:24:01Z"],["dc.date.available","2021-12-01T09:24:01Z"],["dc.date.issued","2021"],["dc.description.abstract","Abstract The spatial features of ultrafast changes in magnetic textures carry detailed information on microscopic couplings and energy transport mechanisms. Electrons excel in imaging such picosecond or shorter processes at nanometer length scales. We review the range of physical interactions that produce ultrafast magnetic contrast with electrons, and specifically highlight the recent emergence of ultrafast Lorentz transmission electron microscopy. From the fundamental processes involved in demagnetization at extremely short timescales to skyrmion-based devices, we show that ultrafast electron imaging will be a vital tool in solving pressing problems in magnetism and magnetic materials where nanoscale inhomogeneity, microscopic field measurement, non-equilibrium behavior or dynamics are involved. Graphic abstract"],["dc.identifier.doi","10.1557/s43577-021-00166-5"],["dc.identifier.pii","166"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/94825"],["dc.language.iso","en"],["dc.notes.intern","DOI-Import GROB-478"],["dc.relation","SFB 1073: Kontrolle von Energiewandlung auf atomaren Skalen"],["dc.relation","SFB 1073 | Topical Area A: Control of dissipation"],["dc.relation","SFB 1073 | Topical Area A | A05 Nanoskalige Untersuchung raumzeitlicher Relaxation in heterogenen Systemen mit ultraschneller Transmissionselektronenmikroskopie"],["dc.relation.eissn","1938-1425"],["dc.relation.issn","0883-7694"],["dc.rights","CC BY 4.0"],["dc.title","Ultrafast electron microscopy for probing magnetic dynamics"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.subtype","original_ja"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","L032036"],["dc.bibliographiccitation.firstpage","1"],["dc.bibliographiccitation.issue","3"],["dc.bibliographiccitation.journal","Physical Review Research"],["dc.bibliographiccitation.lastpage","7"],["dc.bibliographiccitation.volume","3"],["dc.contributor.author","Yalunin, Sergey V."],["dc.contributor.author","Feist, Armin"],["dc.contributor.author","Ropers, Claus"],["dc.date.accessioned","2021-12-01T10:55:35Z"],["dc.date.available","2021-12-01T10:55:35Z"],["dc.date.issued","2021-03-19"],["dc.description.abstract","Temporally shaping the density of electron beams using light forms the basis for a wide range of established and emerging technologies, including free-electron lasers and attosecond electron microscopy. The modulation depth of compressed electron pulses is a key figure of merit limiting applications. In this work, we present an approach for generating background-free attosecond electron pulse trains by sequential inelastic electron-light scattering. Harnessing quantum interference in the fractional Talbot effect, we suppress unwanted background density in electron compression by several orders of magnitude. Our results will greatly enhance applications of coherent electron-light scattering, such as stimulated cathodoluminescence and streaking."],["dc.identifier.arxiv","2103.10921v2"],["dc.identifier.doi","10.1103/PhysRevResearch.3.L032036"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/94900"],["dc.language.iso","en"],["dc.relation","SFB 1456: Mathematik des Experiments: Die Herausforderung indirekter Messungen in den Naturwissenschaften"],["dc.relation","SFB 1456 | Cluster C | C01: Density matrix reconstructions in ultrafast free electron optics"],["dc.relation.issn","2643-1564"],["dc.rights","CC BY 4.0"],["dc.title","Tailored high-contrast attosecond electron pulses for coherent excitation and scattering"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.subtype","original_ja"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","63"],["dc.bibliographiccitation.journal","Ultramicroscopy"],["dc.bibliographiccitation.lastpage","73"],["dc.bibliographiccitation.volume","176"],["dc.contributor.author","Feist, Armin"],["dc.contributor.author","Bach, Nora"],["dc.contributor.author","da Silva, Nara Rubiano"],["dc.contributor.author","Danz, Thomas"],["dc.contributor.author","Möller, Marcel"],["dc.contributor.author","Priebe, Katharina E."],["dc.contributor.author","Domröse, Till"],["dc.contributor.author","Gatzmann, J. Gregor"],["dc.contributor.author","Rost, Stefan"],["dc.contributor.author","Schauss, Jakob"],["dc.contributor.author","Strauch, Stefanie"],["dc.contributor.author","Bormann, Reiner"],["dc.contributor.author","Sivis, Murat"],["dc.contributor.author","Schäfer, Sascha"],["dc.contributor.author","Ropers, Claus"],["dc.date.accessioned","2018-11-07T10:23:59Z"],["dc.date.accessioned","2020-02-03T09:08:33Z"],["dc.date.available","2018-11-07T10:23:59Z"],["dc.date.available","2020-02-03T09:08:33Z"],["dc.date.issued","2017"],["dc.description.abstract","We present the development of the first ultrafast transmission electron microscope (UTEM) driven by localized photoemission from a field emitter cathode. We describe the implementation of the instrument, the photoemitter concept and the quantitative electron beam parameters achieved. Establishing a new source for ultrafast TEM, the Göttingen UTEM employs nano-localized linear photoemission from a Schottky emitter, which enables operation with freely tunable temporal structure, from continuous wave to femtosecond pulsed mode. Using this emission mechanism, we achieve record pulse properties in ultrafast electron microscopy of 9Å focused beam diameter, 200fs pulse duration and 0.6eV energy width. We illustrate the possibility to conduct ultrafast imaging, diffraction, holography and spectroscopy with this instrument and also discuss opportunities to harness quantum coherent interactions between intense laser fields and free-electron beams."],["dc.identifier.arxiv","1611.05022v1"],["dc.identifier.doi","10.1016/j.ultramic.2016.12.005"],["dc.identifier.isi","000403992200010"],["dc.identifier.pmid","28139341"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/42570"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/62933"],["dc.language.iso","en"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","PUB_WoS_Import"],["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.eissn","1879-2723"],["dc.relation.issn","0304-3991"],["dc.rights","CC BY-NC-ND 4.0"],["dc.title","Ultrafast transmission electron microscopy using a laser-driven field emitter: Femtosecond resolution with a high coherence electron beam"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.subtype","original_ja"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","031052"],["dc.bibliographiccitation.issue","3"],["dc.bibliographiccitation.journal","Physical Review. X, Expanding Access"],["dc.bibliographiccitation.volume","8"],["dc.contributor.author","da Silva, Nara Rubiano"],["dc.contributor.author","Möller, Marcel"],["dc.contributor.author","Feist, Armin"],["dc.contributor.author","Ulrichs, Henning"],["dc.contributor.author","Ropers, Claus"],["dc.contributor.author","Schäfer, Sascha"],["dc.date.accessioned","2021-10-15T08:42:42Z"],["dc.date.available","2021-10-15T08:42:42Z"],["dc.date.issued","2017-10-09"],["dc.description.abstract","Novel time-resolved imaging techniques for the investigation of ultrafast nanoscale magnetization dynamics are indispensable for further developments in light-controlled magnetism. Here, we introduce femtosecond Lorentz microscopy, achieving a spatial resolution below 100 nm and a temporal resolution of 700 fs, which gives access to the transiently excited state of the spin system on femtosecond timescales and its subsequent relaxation dynamics. We demonstrate the capabilities of this technique by spatio-temporally mapping the light-induced demagnetization of a single magnetic vortex structure and quantitatively extracting the evolution of the magnetization field after optical excitation. Tunable electron imaging conditions allow for an optimization of spatial resolution or field sensitivity, enabling future investigations of ultrafast internal dynamics of magnetic topological defects on 10-nanometer length scales."],["dc.identifier.doi","10.1103/PhysRevX.8.031052"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/16676"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/90940"],["dc.identifier.url","https://publications.goettingen-research-online.de/handle/2/61695"],["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","SFB 1073 | Topical Area A | A06"],["dc.relation.issn","2160-3308"],["dc.rights","CC BY 4.0"],["dc.title","Nanoscale mapping of ultrafast magnetization dynamics with femtosecond Lorentz microscopy"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.subtype","original_ja"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]