Geometric phase from Aharonov-Bohm to Pancharatnam–Berry and beyond Eliahu Cohen1,2,*, Hugo Larocque1, Frédéric Bouchard1, Farshad Nejadsattari1, Yuval Gefen3, Ebrahim Karimi1,* 1Department of Physics, University of Ottawa, Ottawa, Ontario, K1N 6N5, Canada 2Faculty of Engineering and the Institute of Nanotechnology and Advanced Materials, Bar Ilan University, Ramat Gan 5290002, Israel 3Department of Condensed Matter Physics, Weizmann Institute of Science, Rehovot 76100, Israel *Corresponding authors:
[email protected],
[email protected] Abstract: Whenever a quantum system undergoes a cycle governed by a slow change of parameters, it acquires a phase factor: the geometric phase. Its most common formulations are known as the Aharonov-Bohm, Pancharatnam and Berry phases, but both prior and later manifestations exist. Though traditionally attributed to the foundations of quantum mechanics, the geometric phase has been generalized and became increasingly influential in many areas from condensed-matter physics and optics to high energy and particle physics and from fluid mechanics to gravity and cosmology. Interestingly, the geometric phase also offers unique opportunities for quantum information and computation. In this Review we first introduce the Aharonov-Bohm effect as an important realization of the geometric phase. Then we discuss in detail the broader meaning, consequences and realizations of the geometric phase emphasizing the most important mathematical methods and experimental techniques used in the study of geometric phase, in particular those related to recent works in optics and condensed-matter physics. Published in Nature Reviews Physics 1, 437–449 (2019). DOI: 10.1038/s42254-019-0071-1 1. Introduction A charged quantum particle is moving through space.