We investigate a two-dimensional classical N-vector model with a generic nearest-neighbor interaction W( sigma i middot sigma j)in the large-N limit, focusing on the finite-temperature transition point at which energy-energy correlations become critical. We show that this transition belongs to the Ising universality class. However, the width of the region in which Ising behavior is observed scales as 1/N32/ along the magnetic direction and as 1/N in the thermal direction; outside a crossover to mean-field behavior occurs. This explains why only mean-field behavior is observed for N= infinity.
Two-dimensional Heisenberg model with nonlinear interactions: 1/N corrections / Sergio Caracciolo, Bortolo Matteo Mognetti, Andrea Pelissetto. - In: NUCLEAR PHYSICS. B. - ISSN 0550-3213. - 707:3(2005), pp. 458-492. [10.1016/j.nuclphysb.2004.11.027]
Two-dimensional Heisenberg model with nonlinear interactions: 1/N corrections
S. Caracciolo;B.M. Mognetti;
2005
Abstract
We investigate a two-dimensional classical N-vector model with a generic nearest-neighbor interaction W( sigma i middot sigma j)in the large-N limit, focusing on the finite-temperature transition point at which energy-energy correlations become critical. We show that this transition belongs to the Ising universality class. However, the width of the region in which Ising behavior is observed scales as 1/N32/ along the magnetic direction and as 1/N in the thermal direction; outside a crossover to mean-field behavior occurs. This explains why only mean-field behavior is observed for N= infinity.Pubblicazioni consigliate
I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.