dc.contributor.advisor | Ropers, Claus Prof. Dr. | |
dc.contributor.author | Rubiano da Silva, Nara | |
dc.date.accessioned | 2019-05-08T08:52:24Z | |
dc.date.available | 2019-05-08T08:52:24Z | |
dc.date.issued | 2019-05-08 | |
dc.identifier.uri | http://hdl.handle.net/11858/00-1735-0000-002E-E628-A | |
dc.identifier.uri | http://dx.doi.org/10.53846/goediss-7437 | |
dc.language.iso | eng | de |
dc.rights.uri | http://creativecommons.org/licenses/by-nc-nd/4.0/ | |
dc.subject.ddc | 530 | de |
dc.title | Ultrafast Lorentz Microscopy using High-Coherence Electron Pulses | de |
dc.type | doctoralThesis | de |
dc.contributor.referee | Ropers, Claus Prof. Dr. | |
dc.date.examination | 2019-03-29 | |
dc.subject.gok | Physik (PPN621336750) | de |
dc.description.abstracteng | Information processing and storage applications demand increasing miniaturization
and operation speeds, where optical manipulation of magnetic order may play a
very important role. It is hence essential to study how light stimulates magnetization
reordering at very short spatial and temporal scales. The development of Ultrafast
Transmission Electron Microscopy (UTEM), a laser-pump/electron-probe setup,
provides a unique means for that. However, magnetic information can only be
visualized in UTEM provided a spatially coherent pulsed electron source is available,
since phase-contrast techniques such as Lorentz microscopy are required. In this
work, highly coherent electron pulses are achieved by implementing a laser-driven
Schottky field emitter in UTEM. We employ the electron pulses to map the ultrafast
demagnetization of a single magnetic structure with very high spatial and temporal
resolution. We show that the transient magnetization can be quantitatively tracked
from the image contrast, and that the magnetic order remains rigid with decreased
strength on short timescales following the optical excitation. This work builds a
solid framework for the acquisition, and quantitative evaluation and interpretation
of magnetic contrast images of transient magnetic states. Moreover, it establishes
magnetic imaging with high spatiotemporal resolution, and constitutes a step forward
in ultrafast phase-contrast imaging on the nanoscale. | de |
dc.contributor.coReferee | Mathias, Stefan Prof. Dr. | |
dc.subject.eng | Ultrafast transmission electron microscopy | de |
dc.subject.eng | UTEM | de |
dc.subject.eng | Coherent ultrashort electron pulses | de |
dc.subject.eng | Nanoscale magnetization dynamics | de |
dc.subject.eng | Lorentz microscopy | de |
dc.subject.eng | Magnetic imaging | de |
dc.subject.eng | Ultrafast dynamics | de |
dc.subject.eng | Ultrafast solid-state physics | de |
dc.identifier.urn | urn:nbn:de:gbv:7-11858/00-1735-0000-002E-E628-A-0 | |
dc.affiliation.institute | Fakultät für Physik | de |
dc.identifier.ppn | 1666650900 | |