Karl Franzens University Graz

Graz University of Technology 

Free-electron wavepackets interacting with light
Nahid Talebi
Institute for Experimental and Applied Physics, Kiel University
16:15 - 17:15 Tuesday 11 January 2022 KFU

Video: https://us02web.zoom.us/j/81869672531

Recent advances in electron-beam science have pushed a new era for nanooptics, by merging laser and electron beam spectroscopies in a single apparatus. This new domain, the so-called photon-induced near-field electron microscopy [1], concerns quantum-mechanical electron-light interactions and allows for shaping the swift electron wavepackets on demand, by virtue of near-field oscillations. In this talk, I describe the physics of electron-beam spectroscopy techniques and provides examples covering plasmon and exciton polaritons in conventional and van der Waals nanostructures [2]. The mechanisms of radiation from electron beams interacting with structured materials will be covered with the aim to shape the electron-induced radiation [3, 4], for applications in new kinds of electron-photon conjugate spectroscopy techniques. In additions, I will show what kind of new physics we can learn by merging laser and electron pulses, highlighting particularly generalized Kapitza-Dirac effect [5], strong electron-light interactions [6] (Fig. 1), as well as spectroscopy with electron-beam superposition and entangled electron beams [7].


Fig. 1. Simulated inelastic scattering cross section for an initially Gaussian electron wavepacket at the kinetic energy of 400 eV interacting with laser induced localized plasmons of a gold nanorod. For more information, see ref. [6].



References
[1] B. Barwick, D. J. Flanningen, and A. H. Zewail, “Photon-induced near-field electron microscopy,” Nature 462, 902–906 (2009)
[2] N. Talebi, Near-field mediated photon-electron interactions, Springer, Berlin (2019)
[3] N. van Nielen, M. Hentschel, N. Schilder, H. Giessen, A. Polman, N. Talebi, “Electrons generate self-complementary broadband vortex light beams using chiral photon sieves,” Nano Letters 20 (8), 5975-5981 (2020)
[4] N. Talebi, S. Meuret, S. Guo, M. Hentschel, A. Polman, H. Giessen, P. A. van Aken, “Merging transformation optics with electron-driven photon sources,” Nature communications 10 (1), 1-8 (2019)
[5] N. Talebi and C. Lienau, “Interference between quantum paths in coherent Kapitza–Dirac effect,” New Journal of Physics 21 (9), 093016 (2019)
[6] N. Talebi, “Strong interaction of slow electrons with near-field light visited from first principles,” Physical Review Letters 125, 080401 (2020)
[7] N. Talebi and I. Brezinova, “Exchange-Mediated Mutual Correlations and Dephasing in Free-Electrons and Light Interactions,” New Journal of Physics 23, 063066 (2021)