Title | Second Chern number of a quantum-simulated non-Abelian Yang monopole |
Publication Type | Journal Article |
Year of Publication | 2018 |
Authors | S. Sugawa, F. Salces-Carcoba, A. R. Perry, Y. Yue, and I. B. Spielman |
Journal | Science |
Volume | 360 |
Pagination | 1429–1434 |
ISSN | 0036-8075 |
Abstract | Topological properties of physical systems are reflected in so-called Chern numbers: A nonzero Chern number typically means that a system is topologically nontrivial. Sugawa et al. engineered a cold atom system with a nonzero second Chern number, in contrast to condensed matter physics, where only the first Chern number is usually invoked. The exotic topology relates to the emergence of a type of magnetic monopole called the Yang monopole (known from theoretical high-energy physics) in a five-dimensional space of internal degrees of freedom in a rubidium Bose-Einstein condensate. The results illustrate the potential of cold atoms physics to simulate high-energy phenomena.Science, this issue p. 1429Topological order is often quantified in terms of Chern numbers, each of which classifies a topological singularity. Here, inspired by concepts from high-energy physics, we use quantum simulation based on the spin degrees of freedom of atomic Bose-Einstein condensates to characterize a singularity present in five-dimensional non-Abelian gauge theories—a Yang monopole. We quantify the monopole in terms of Chern numbers measured on enclosing manifolds: Whereas the well-known first Chern number vanishes, the second Chern number does not. By displacing the manifold, we induce and observe a topological transition, where the topology of the manifold changes to a trivial state. |
URL | http://science.sciencemag.org/content/360/6396/1429 |
DOI | 10.1126/science.aam9031 |