Non-Abelian Ferromagnets

by Prof. Konstantinos Sfetsos (National and Kapodistrian University of Athens (GR))

Friday May 24, 2024, 11:00 AM → 12:00 PM Europe/Athens

B228 (ΘΕΕ02)

Abstract: A model of a non-Αbelian ferromagnet consisting of “atoms” each carrying a fundamental representation of SU(N) coupled with long-range two-body quadratic interactions is presented.  Studying the thermodynamics, a rich structure of phase transitions from non-magnetized, global SU(N)-invariant states to magnetized ones breaking global invariance to SU(N−1) x U(1) is uncovered. Phases can coexist, one being stable and the other metastable, and the transition between states involves latent heat exchange, unlike in usual SU(2) ferromagnets. The system manifests hysteresis phenomena. Furthermore, we study the multiplicity of irreducible representations in the decomposition of n fundamentals of SU(N) weighted by a power of their dimension in the large n,N double scaling limit in which the ratio n/N² is kept fixed, playing the role of an order parameter. We uncover phase transitions of varying order in this parameter, from a dense phase to a dilute phase.

U. of Cyprus [24-5-2024].pdf