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arXiv:1406.5674

Waiting for the Quantum Bus

Anthony J. Bracken, G.F. Melloy

Published Jun 22, 2014• 2 citations
arXivHTMLPDF

Abstract

Forty-five years after the discovery of the peculiar quantum effect known as `probability backflow', and twenty years after the greatest possible size of the effect was characterized, an experiment has been proposed recently to observe the effect in a Bose-Einstein condensate. Here the history is described in non-technical terms.
DOI
10.48550/arxiv.1406.5674

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Bose-Einstein Condensation is a phenomenon at the heart of many of the past century's most intriguing and fundamental manifestations, such as superfluidity and superconductivity: it was discovered theoretically some 100 years ago, and unequivocally experimentally demonstrated in the context of weakly-interacting gases 30 years ago. Since then, it has revolutionised our understanding of the collective quantum behaviour of matter. Such a phenomenon manifests itself across all physical scales, from the nuclear and atomic, all the way to the astrophysical, and has paved the way for novel technological applications.
Bose-Einstein condensation, or BEC, has a long and rich history dating from the early 1920s. In this article we will trace briefly over this history and some of the developments in physics that made possible our successful pursuit of BEC in a gas. We will then discuss what was involved in this quest. In this discussion we will go beyond the usual technical description to try and address certain questions that we now hear frequently, but are not covered in our past research papers. These are questions along the lines of: How did you get the idea and decide to pursue it? Did you know it was going to work? How long did it take you and why? We will review some our favorites from among the experiments we have carried out with BEC. There will then be a brief encore on why we are optimistic that BEC can be created with nearly any species of magnetically trappable atom. Throughout this article we will try to explain what makes BEC in a dilute gas so interesting, unique, and experimentally challenging.1{\mathrm{challenging}.}^{1}challenging.1
© The Author(s) 2025.Bose-Einstein Condensation is a phenomenon at the heart of many of the past century’s most intriguing and fundamental manifestations, such as superfluidity and superconductivity: it was discovered theoretically some 100 years ago, and unequivocally experimentally demonstrated in the context of weakly-interacting gases 30 years ago. Since then, it has revolutionised our understanding of the collective quantum behaviour of matter. Such a phenomenon manifests itself across all physical scales, from the nuclear and atomic, all the way to the astrophysical, and has paved the way for novel technological applications.