Entropy and free energy of the spin glass in the random-bond Ising model on the square lattice at finite temperatures

1982 ◽  
Vol 116 (3) ◽  
pp. 622
Author(s):  
Nahomi Miyamoto ◽  
Shigetoshi Katsura
1989 ◽  
Vol 03 (07) ◽  
pp. 1119-1128
Author(s):  
K.Y. LIN ◽  
K.J. HSU

We have considered the Ising model on a layered square lattice where each layer has a different set of horizontal and vertical interactions. The free energy is determined exactly by the method of Pfaffian at two values of the magnetic field, H=0 and H=iπkT/2. The free energy at H=0 was first derived by Wolff et al. using the method of transfer matrix.


2019 ◽  
Vol 7 (3) ◽  
Author(s):  
Hendrik Hobrecht ◽  
Fred Hucht

We present detailed calculations for the partition function and the free energy of the finite two-dimensional square lattice Ising model with periodic and antiperiodic boundary conditions, variable aspect ratio, and anisotropic couplings, as well as for the corresponding universal free energy finite-size scaling functions. Therefore, we review the dimer mapping, as well as the interplay between its topology and the different types of boundary conditions. As a central result, we show how both the finite system as well as the scaling form decay into contributions for the bulk, a characteristic finite-size part, and – if present – the surface tension, which emerges due to at least one antiperiodic boundary in the system. For the scaling limit we extend the proper finite-size scaling theory to the anisotropic case and show how this anisotropy can be absorbed into suitable scaling variables.


Author(s):  
Rodney J. Baxter

We consider the anisotropic Ising model on the triangular lattice with finite boundaries, and use Kaufman’s spinor method to calculate low-temperature series expansions for the partition function to high order. From these, we can obtain 108-term series expansions for the bulk, surface and corner free energies. We extrapolate these to all terms and thereby conjecture the exact results for each. Our results agree with the exactly known bulk-free energy and with Cardy and Peschel’s conformal invariance predictions for the dominant behaviour at criticality. For the isotropic case, they also agree with Vernier and Jacobsen’s conjecture for the 60 ° corners.


1981 ◽  
Vol 85 (5) ◽  
pp. 301-302
Author(s):  
V.A. Moskalenko ◽  
L.A. Dogotar ◽  
M.I. Vladimir
Keyword(s):  

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