2020/02/29 by Adu Offei-Danso, Federica Maria Surace, Fernando Iemini +2 · 1 citation
Physics and Astronomy · #cond-mat.stat-mech
paper · pdf · doi:10.1088/1742-5468/aba0a1
published as Jour. Stat. Mech. 2020, 073107 (2020)
arxiv created 2020/06/03 · arxiv updated 2020/08/04
We study the phase diagram, both at zero and finite temperature, in a class of ℤq models with infinite range interactions. We are able to identify the transitions between a symmetry-breaking and a trivial phase by using a mean-field approach and a perturbative expansion. We perform our analysis on a Hamiltonian with 2p-body interactions and we find first-order transitions for any p>1; in the case p=1, the transitions are first-order for q=3 and second-order otherwise. In the infinite-range case there is no trace of gapless incommensurate phase but, when the transverse field is maximally chiral, the model is in a symmetry-breaking phase for arbitrarily large fields. We analytically study the transtion in the limit of infinite q, where the model possesses a continuous U(1) symmetry.