Guimarães P R C, Plascak J A, de Alcantara Bonfim O F, Florencio J
Departamento de Física, Universidade Federal de Viçosa, 36571-000 Viçosa, Minas Gerais, Brazil.
Universidade Federal da Paraíba, Centro de Ciências Exatas e da Natureza-Campus I, Departamento de Física, CCEN Cidade Universitária-João Pessoa, PB, Brazil and Department of Physics and Astronomy, University of Georgia, 30602 Athens, Georgia, USA.
Phys Rev E Stat Nonlin Soft Matter Phys. 2015 Oct;92(4):042115. doi: 10.1103/PhysRevE.92.042115. Epub 2015 Oct 7.
We study the effects of next-nearest-neighbor (NNN) interactions on the dynamics of the one-dimensional spin-1/2 transverse Ising model in the high-temperature limit. We use exact diagonalization to obtain the time-dependent transverse correlation function and the corresponding spectral density for a tagged spin. Our results for chains of 13 spins with periodic boundary conditions produce results which are valid in the infinite-size limit. In general we find that the NNN coupling produces slower dynamics accompanied by an enhancement of the central mode behavior. Even in the case of a strong transverse field, if the NNN coupling is sufficiently large, then there is a crossover from collective mode to central mode behavior. We also obtain several recurrants for the continued fraction representation of the relaxation function.
