We study the two-dimensional fully frustrated XY (FFXY) model and two related models, a discretization of the Landau-Ginzburg-Wilson Hamiltonian for the critical modes of the FFXY model and a coupled Ising-XY model, by means of Monte Carlo simulations on square lattices L-2, L less than or similar to 10(3). We show that their phase diagram is characterized by two very close chiral and spin transitions, at T-ch> T-sp respectively, of the Ising and Kosterlitz-Thouless type. At T-ch the Ising regime sets in only after a preasymptotic regime, which appears universal to some extent. The approach is nonmonotonic for most observables, with a wide region controlled by an effective exponent nu(eff)approximate to 0.8.
Transitions and crossover phenomena in fully frustrated XY systems / Martin, Hasenbusch; Pelissetto, Andrea; Ettore, Vicari. - In: PHYSICAL REVIEW. B, CONDENSED MATTER AND MATERIALS PHYSICS. - ISSN 1098-0121. - STAMPA. - 72:18(2005), p. 184502. [10.1103/physrevb.72.184502]
Transitions and crossover phenomena in fully frustrated XY systems
PELISSETTO, Andrea;
2005
Abstract
We study the two-dimensional fully frustrated XY (FFXY) model and two related models, a discretization of the Landau-Ginzburg-Wilson Hamiltonian for the critical modes of the FFXY model and a coupled Ising-XY model, by means of Monte Carlo simulations on square lattices L-2, L less than or similar to 10(3). We show that their phase diagram is characterized by two very close chiral and spin transitions, at T-ch> T-sp respectively, of the Ising and Kosterlitz-Thouless type. At T-ch the Ising regime sets in only after a preasymptotic regime, which appears universal to some extent. The approach is nonmonotonic for most observables, with a wide region controlled by an effective exponent nu(eff)approximate to 0.8.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
