Jim and Randy discuss quasiparticles recently found in condensed matter systems that mirror particles theorized nearly a hundred years ago, but never found in the vacuum. Weyl particles are massless fermions, and once it was hoped that neutrinos would turn out to be this kind of particle, and Majorana fermions have real-valued wave functions and therefore many strange and possibly useful properties.

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Notes:

1. The papers we read for this program:

- Pal, P.B., "Dirac, Majorana, and Weyl Fermions."
*Am. J. Phys*.**79**, 485 (2011). [arXiv] - Mourik, Zuo, Frolov, Plissard, Bakkers, and Kouwenhoven, "Signatures of Majorana Fermions in Hybrid Superconductor-Semiconductor Nanowire Devices."
*Science***336**, 1003 (2012). [arXiv] - Nadj-Perge, Drozdov, Li, Chen, Jeon, Seo, MacDonald, Bernevig, and Yazsdani, "Observation of Majorana Fermions in Ferromagnetic Atomic Chains of a Superconductor."
*Science***346**, 602 (2014) [arXiv] - Xu, et al., "Discovery of a Weyl Fermion State with Fermi Arcs in Niobium Arsenide."
*Nat. Phys.***11**, 748 (2015) [arXiv] - Zhang, et al, "Signatures of the Adler-Bell-Jackiw Chiral Anomaly in a Weyl Fermion Semimetal."
*Nat. Comm.*10735 (2016) [arXiv]

- Wilczek, F., "Why are there Analogies between Condensed Matter and Particle Theory?"
*Physics Today***51**, 11 (1998). - Wilczek, F., "Majorana Returns."
*Nature Physics***5**, 614 (2009) - Balents, Leon, "Weyl Electrons Kiss."
*Physics***4**, 36 (2011). - "After a Weyl" Nat. Phys. 11, 697 (2015)
- Bernevig, B.A., "It's Been a Weyl Coming." Nat. Phys. 11, 699 (2015)

- Weyl, H., "Gravitation and the Electron." Proc. Nat. Acad. Sci., 323 (1929).
- Majorana, "A Symmetric Theory of Electrons and Positrons." Il Nuovo Cimento, 14, 171 (1937).

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