2002/12/24 by Hidetsugu Kitatani, H. Kitatani, T. Chino +6
Economics, Econometrics and Finance · Mathematics · Physics and Astronomy · #Complex Systems and Time Series Analysis #Condensed matter physics #Degeneracy (biology) #Disordered Systems and Neural Networks (cond-mat.dis-nn) #FOS: Physical sciences #Ferromagnetism #Geometry #Ground state #Ising model #Mathematics #Monte Carlo method #Opinion Dynamics and Social Influence #Paramagnetism #Physics #Plane (geometry) #Quantum mechanics #Statistical Mechanics (cond-mat.stat-mech) #Statistical physics #Statistics #Theoretical and Computational Physics #Thermodynamics #cond-mat.dis-nn #cond-mat.stat-mech
paper · pdf · doi:10.48550/arxiv.cond-mat/0212579
12 pages, 6 figures, submitted to J. Phys. A
arxiv created 2002/12/24 · openalex publication_date 2002/12/24 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The specific heat of the two-dimensional ± J Ising model has been investigated by the numerical transfer matrix method and Monte Carlo simulations from a new point of view. The region where a part of the specific heat takes the negative value has been investigated, which is characteristic of frustrated systems and reflects the non-trivial degeneracy of the ground state. The region mentioned above is found to be fairly large in the p-T plane (p is the concentration of the ferromagnetic bond and T is the temperature). Moreover, it includes the Nishimori line. Namely, it includes a part of the paramagnetic-ferromagnetic phase boundary, on which the specific heat cannot diverge. The present result indicates that the specific heat does not diverge at least on a part of the paramagnetic-ferromagnetic phase boundary above the multicritical point, which is in conflict with previous results.