The exact phase diagrams of spin-1 Ising model on a two-layer Bethe lattice

✍ Scribed by Erhan Albayrak; Osman Canko

• Publisher: Elsevier Science
• Year: 2007
• Tongue: English
• Weight: 431 KB
• Volume: 373
• Category: Article
• ISSN: 0378-4371
• DOI: 10.1016/j.physa.2006.04.114

✦ Synopsis

The two-layer spin-1 Ising model on the Bethe lattice is studied in terms of the intralayer coupling constants J 1 and J 2 of the two layers, interlayer coupling constant J 3 between the layers and the external magnetic fields, which are coupled to the two layers and assumed to be different for each layer, for given values of the coordination number q by using the recursion relation scheme. The ground-state configurations of the system are obtained on the ðJ 2 =jJ 1 j; J 3 =qjJ 1 jÞ planes depending on J 1 o0 or J 1 40. Then, the phase diagram of the system is obtained on the ðkT=J 1 ; J 3 =J 1 Þ plane for given values of a ¼ J 2 =J 1 and q in zero external magnetic fields. It was found that the system presents both first-and second-order phase transitions for all values of q. Besides, we also present the thermal change of the total and staggered magnetizations of the two layers and also the spin-spin correlation function between the nearest-neighbor spins of the adjacent layers.