Regensburg 2019 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 11: Focus: Advanced TEM spectroscopy - low energy excitations and chemical composition at high resolution (joint session KFM/HL)

HL 11.6: Hauptvortrag

Montag, 1. April 2019, 17:10–17:40, PHY 5.0.20

Advanced Imaging and Spectroscopy in an Ultrafast Transmission Electron Microscope — •Armin Feist — IV. Physical Institute, University of Göttingen, 37077 Göttingen, Germany

Electron microscopy is tremendously successful in studying complex nanostructured systems, with a temporal resolution governed by typical detector response times. Overcoming these time-domain limitations, ultrafast transmission electron microscopy (UTEM) combines the versatile imaging, diffraction and spectroscopy capabilities of state-of-the-art TEM with femtosecond temporal resolution achieved by a laser pump/electron probe scheme [1,2].

Here, I will briefly introduce the UTEM methodology and show recent results of the Göttingen UTEM instrument, which features high coherence electron pulses generated from nanoscale field emitter tips [2]. The novel applications of UTEM include the study of coherent inelastic electron-light scattering (IELS) at laser-excited nanostructures [3,4]. Besides nanometer mapping of optical near-fields and plasmonic modes, IELS enables the transverse and longitudinal phase control of the free-electron wavefunction [4,5], as evident from characteristic multiphoton gain and loss spectra. In particular, this new concept now allows us to generate attosecond electron pulse trains with applications for optically phase-resolved electron microscopy [5].

[1] A. H. Zewail, Science 328, 187 (2010). [2] A. Feist et al., Ultramicroscopy 176, 63 (2017). [3] Barwick et al., Nature 462, 902 (2009). [4] A. Feist et al., Nature 521, 200 (2015). [5] K. E. Priebe et al., Nat. Photonics 11, 793 (2017).