1,720,976 research outputs found
Two-dimensional Born-Infeld gauge theory: spectrum, string picture and large-N phase transition
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Triple critical point and emerging temperature scales in SU(N) ferromagnetism at large N
No full textThe non-Abelian ferromagnet recently introduced by the authors, consisting of atoms in the fundamental representation of SU(N), is studied in the limit where N becomes large and scales as the square root of the number of atoms n. This model exhibits additional phases, as well as two different temperature scales related by a factor N/lnN. The paramagnetic phase splits into a “dense” and a “dilute” phase, separated by a third-order transition and leading to a triple critical point in the scale parameter n/N2 and the temperature, while the ferromagnetic phase exhibits additional structure, and a new paramagnetic-ferromagnetic metastable phase appears at the larger temperature scale. These phases can coexist, becoming stable or metastable as temperature varies. A generalized model in which the number of SU(N)-equivalent states enters the partition function with a nontrivial weight, relevant, e.g., when there is gauge invariance in the system, is also studied and shown to manifest similar phases, the dense-dilute phase transition becoming second-order in the fully gauge invariant case
Nonabelian ferromagnets with three-body interactions
No full textWe study the thermodynamics of nonabelian ferromagnets consisting of atoms in the fundamental representation of SU(N) and interacting with two-body and three-body interactions. Using a mean field approach, we uncover an intricate phase structure, depending on the relative strength and sign of the two-body and three-body coupling constants. In the case where two-body interactions are ferromagnetic and three-body ones are antiferromagnetic, we uncover a rich cascade of phase transitions, the appearance of phases with two distinct polarization directions being the most striking novel feature. Our results are relevant to magnetic systems where higher-body interactions cannot be neglected
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