Contributor info: Prof. Klaas Landsman

Christiaan J. F. van de Ven, Gerrit C. Groenenboom, Robin Reuvers, Nicolaas P. Landsman

SciPost Phys. 8, 022 (2020) · published 6 February 2020 | Toggle abstract · pdf

Spontaneous symmetry breaking (SSB) is mathematically tied to some limit, but must physically occur, approximately, before the limit. Approximate SSB has been independently understood for Schroedinger operators with double well potential in the classical limit (Jona-Lasinio et al, 1981; Simon, 1985) and for quantum spin systems in the thermodynamic limit (Anderson, 1952; Tasaki, 2019). We relate these to each other in the context of the Curie-Weiss model, establishing a remarkable relationship between this model (for finite N) and a discretized Schroedinger operator with double well potential.