Aleksandr Silenko (BLTP JINR) "New quantum-mechanical effect and its application to production of twisted particle beams"
In quantum mechanics, contrary to the classical picture, the particle has a nonzero radial momentum and there exists the new effect of a change of its quantum-mechanical state. The angular velocity of particle revolution, ω, does not commute with the Hamiltonian. Promptly after the penetration to the solenoid, the particle revolution is characterized by a definite phase. After some revolutions number of which depends on the dispersion of ω, the particle is already in one of the twisted Landau states. As has been previously shown by Floetmann and Karlovets (2020), such a particle remains twisted after the penetration from the solenoid to the vacuum.
We show that the found quantum-mechanical effect can be practically used for a production of twisted particle beams in a wide energy range, including beams of new twisted particles.
Wikipedia:
Orbital angular momentum of free electrons
Measurement
Interferometric methods borrowed from light optics also work to determine the orbital angular momentum of free electrons in pure states. Interference with a planar reference wave,[5] diffractive filtering and self-interference[15][16][17] can serve to characterize a prepared electron orbital angular momentum state. In order to measure the orbital angular momentum of a superposition or of the mixed state that results from interaction with an atom or material, a non-interferometric method is necessary. Wavefront flattening,[17][18] transformation of an orbital angular momentum state into a planar wave,[19] or cylindrically symmetric Stern-Gerlach-like measurement[20] is necessary to measure the orbital angular momentum mixed or superposition state.
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18. Saitoh, Koh; Hasegawa, Yuya; Hirakawa, Kazuma; Tanaka, Nobuo; Uchida, Masaya (2013-08-14). "Measuring the Orbital Angular Momentum of Electron Vortex Beams Using a Forked Grating". Physical Review Letters. 111 (7): 074801. arXiv:1307.6304. Bibcode:2013PhRvL.111g4801S. doi:10.1103/PhysRevLett.111.074801. PMID 23992070. S2CID 37702862.
19. McMorran, Benjamin J.; Harvey, Tyler R.; Lavery, Martin P. J. (2017). "Efficient sorting of free electron orbital angular momentum". New Journal of Physics. 19 (2): 023053. arXiv:1609.09124. Bibcode:2017NJPh...19b3053M. doi:10.1088/1367-2630/aa5f6f. S2CID 119192171. Grillo, Vincenzo; Tavabi, Amir H.; Venturi, Federico; Larocque, Hugo; Balboni, Roberto; Gazzadi, Gian Carlo; Frabboni, Stefano; Lu, Peng-Han; Mafakheri, Erfan; Bouchard, Frédéric; Dunin-Borkowski, Rafal E.; Boyd, Robert W.; Lavery, Martin P. J.; Padgett, Miles J.; Karimi, Ebrahim (2017-05-24). "Measuring the orbital angular momentum spectrum of an electron beam". Nature Communications. 8: 15536. Bibcode:2017NatCo...815536G. doi:10.1038/ncomms15536. PMC 5458084. PMID 28537248.
20. Harvey, Tyler R.; Grillo, Vincenzo; McMorran, Benjamin J. (2017-02-28). "Stern-Gerlach-like approach to electron orbital angular momentum measurement". Physical Review A. 95 (2): 021801. arXiv:1606.03631. Bibcode:2017PhRvA..95b1801H. doi:10.1103/PhysRevA.95.021801. S2CID 119086719.
Link to watch the video on the JINR resource:
https://disk.jinr.ru/index.php/s/eyKxAEN28CH4pWQ
Presentation
