Equilibrium and dynamical properties of the axial next nearest-neighbor Ising chain at the multiphase point

Dhar, Abhishek B and Shastry, Sriram and Dasgupta, Chandan (2000) Equilibrium and dynamical properties of the axial next nearest-neighbor Ising chain at the multiphase point. In: Physical Review E, 62 (02). pp. 1592-1600.

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Abstract

We study the equilibrium and dynamical properties of the axial next-nearest-neighbor Ising chain at the multiphase point. An interesting property of the system is the macroscopic degeneracy of the ground state leading to finite zero-temperature entropy. In our equilibrium study we consider the effect of softening the spins. We show that the degeneracy of the ground state is lifted and there is a qualitative change in the low-temperature behavior of the system with a well-defined low-temperature peak of the specific heat that carries the thermodynamic ''weight'' of the ground state entropy. In our study of the dynamical properties, the stochastic Kawasaki dynamics is considered. The Fokker-Planck operator for the process corresponds to a quantum spin Hamiltonian similar to the Heisenberg ferromagnet but with constraints on allowed states. This leads to a number of differences in its properties, which are obtained through exact numerical diagonalization, simulations, and by obtaining various analytic bounds.

Item Type:	Journal Article
Publication:	Physical Review E
Publisher:	American Physical Society
Additional Information:	Copyright of this article belongs to American Physical Society
Department/Centre:	Division of Physical & Mathematical Sciences > Physics
Date Deposited:	17 Jul 2009 07:32
Last Modified:	19 Sep 2010 05:24
URI:	http://eprints.iisc.ac.in/id/eprint/18646

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