Physics Colloquium

It was about 50 years ago today, when "Dislocations in wave trains" [1] came into play.  Twenty years on, "Dislocations" became a '90s hit following the ingenious experiments of Soskin et al. [2],  that showed the promise of applications of "twisted" or structured light, which has non-vanishing orbital angular momentum about its propagation axis. [3-5] Modern use cases for such modalities include increased communication bandwidth for 6G applications.[6]  Quantum particle beams can also be shaped by analogue tools of optics.  I shall present recent results for neutrons, made possible by microfabricated synthetic holograms containing millions of forked dislocation gratings of the type envisaged by Soskin, et al. [7,8]  

[1] "Dislocations in wave trains," J. F. Nye and M. V. Berry, received 17 January 1973, published in Proc. Roy. Soc. Lond. A 366, 165 - 190 (1974)

[2] V. Bazhenov, M. V. Vasnetsov, and M. S. Soskin, “Laser-beams with screw dislocations in their wave-fronts,” JETP. Lett. 52, 429‒ 431 (1990) 

[3] "Roadmap on structured light," H. Rubinsztein-Dunlop, et al., J. Opt. 19, 013001 (2017)

[4] "Optical orbital angular momentum," S. M. Barnett, M. Babiker and M. J. Padgett, Phil. Trans. Roy. Soc. A 375, 20150444 (2017)

[6]  "Roadmap on structured waves," K. Bliokh et al., J. Opt. 25, 103001 (2023) 

[7] "Experimental realization of neutron helical waves," D. Sarenac, M. E. Henderson, H. Ekinci, C. W. Clark, D. G. Cory, L. DeBeer-Schmitt, M. G. Huber, C. Kapahi, D. A. Pushin, Sci. Adv. 8, eadd2002 (2022)

[8] "Cone beam neutron interferometry: from modeling to applications," D. Sarenac, G. Gorbet, C. Kapahi, Charles W. Clark, D. G. Cory, H. Ekinci, S. Fangzhou, M. E. Henderson, M. G. Huber, D. Hussey, P. A. Kienzle, R. Serrat, J. D. Parker, T. Shinohara, D. A. Pushin, arXiv:2309.01787 (2023)