Explanation of the freezing temperature in spin glasses.
Journal of Applied Physics 53 (11), pp. 7682-7683.
The freezing of spins in the two‐dimensional ±J‐model [1,2] (anti‐ and ferromagnetic nearest neighbour bonds between Ising spins) is investigated for the case of a one‐spin‐flip‐dynamic (as used in Monte‐Carlo calculations). The phenomenon is caused by the existence of finite energy barriers between the different ground‐state valleys. The barrier heights are calculated by a numerical method turning one ground state to its inverse. The freezing temperature is determined by the vanishing of the free energy barriers between the valleys. The corresponding entropy is calculated by the Transfermatrix‐Method. The free energy barriers vanish at Tf≂1.3±0.1 in good agreement with the cusp of the susceptibility in Monte‐Carlo calculations. The long‐time behaviour of spin glasses is governed by the mentioned free energy barriers.
|Institutions:|| Physics > Institute of Theroretical Physics > Professor Morgenstern|
|75.10.-b; 75.50.Kj; 75.30.-m||PACS|
|Keywords:||spin glass state, ising model, magnetic−phase transformations, melting points, antiferromagnetism, ferromagnetism, monte carlo method, ground states, entropy, transfer matrix method, free energy|
|Subjects:||500 Science > 530 Physics|
|Created at the University of Regensburg:||Unknown|
|Deposited On:||16 Aug 2010 12:31|
|Last Modified:||20 Jul 2011 22:34|