TY - JOUR

T1 - Phase diagram of an Ising model with competitive interactions on a Husimi tree and its disordered counterpart

AU - Ostilli, M.

AU - Mukhamedov, F.

AU - Mendes, J. F.F.

N1 - Funding Information:
This work was supported by the FCT (Portugal) grants SFRH/BPD/17419/2004, SFRH/BPD/24214/2005, pocTI/FAT/46241/2002 and pocTI/FAT/46176/2003, and the Dysonet Project. We thank A.V. Goltsev and M. Hase, for many useful discussions and a critical reading of the manuscript.

PY - 2008/5/1

Y1 - 2008/5/1

N2 - We consider an Ising competitive model defined over a triangular Husimi tree where loops, responsible for an explicit frustration, are even allowed. We first analyze the phase diagram of the model with fixed couplings in which a "gas of noninteracting dimers (or spin liquid) - ferro or antiferromagnetic ordered state" zero temperature transition is recognized in the frustrated regions. Then we introduce the disorder for studying the spin glass version of the model: the triangular ± J model. We find out that, for any finite value of the averaged couplings, the model exhibits always a finite temperature phase transition even in the frustrated regions, where the transition turns out to be a glassy transition. The analysis of the random model is done by applying a recently proposed method which allows us to derive the critical surface of a random model through a mapping with a corresponding nonrandom model.

AB - We consider an Ising competitive model defined over a triangular Husimi tree where loops, responsible for an explicit frustration, are even allowed. We first analyze the phase diagram of the model with fixed couplings in which a "gas of noninteracting dimers (or spin liquid) - ferro or antiferromagnetic ordered state" zero temperature transition is recognized in the frustrated regions. Then we introduce the disorder for studying the spin glass version of the model: the triangular ± J model. We find out that, for any finite value of the averaged couplings, the model exhibits always a finite temperature phase transition even in the frustrated regions, where the transition turns out to be a glassy transition. The analysis of the random model is done by applying a recently proposed method which allows us to derive the critical surface of a random model through a mapping with a corresponding nonrandom model.

KW - Competing Ising models

KW - Glass transition

KW - Husumi trees

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U2 - 10.1016/j.physa.2008.01.071

DO - 10.1016/j.physa.2008.01.071

M3 - Article

AN - SCOPUS:40249102979

VL - 387

SP - 2777

EP - 2792

JO - Physica A: Statistical Mechanics and its Applications

JF - Physica A: Statistical Mechanics and its Applications

SN - 0378-4371

IS - 12

ER -