Please use this identifier to cite or link to this item: http://repositorio.unicamp.br/jspui/handle/REPOSIP/100121
Type: Artigo de periódico
Title: Long Time Tails In The Dynamics Of The Spatially Inhomogeneous Magnetization Of Dimerized Isotropic Xy Chains For Spin S = 1/2
Author: Berim G.O.
Cabrera G.G.
Abstract: Exact results for the dynamics of the spatially inhomogeneous magnetization (SIM) in the one-dimensional dimerized isotropic XY model are obtained, and the long-time behavior of SIM is considered in detail. It is shown that in the asymptotic limit t → ∞, the time dependence of SIM can be represented as a sum of several components oscillating at different frequencies. Amplitudes of these components decrease according to the (t/τ)-ν power law. It is shown that both, the inverse of the time scale τ-1 and the exponent ν, have critical-like behavior with respect to the wave-vector Q characterizing the spatial inhomogeneity of the initial state. The value of τ-1 goes to zero at |Q| → Qci, where Qci (i = 1,2,3) are critical values of Q determined by parameters of the main Hamiltonian only. Just at points Qc1, Qc2, the exponent ν changes its value discontinuously from ν = 1/2 to ν = 1/4. This effect is very similar to the critical slowing down phenomena in phase transitions. Due to the long-time tails in the relaxation process, we critically discuss the validity of the spin temperature assumption in spin systems.
Editor: 
Rights: fechado
Identifier DOI: 
Address: http://www.scopus.com/inward/record.url?eid=2-s2.0-0031123068&partnerID=40&md5=816800f8859fbd538ad7fc4f4f45816b
Date Issue: 1997
Appears in Collections:Unicamp - Artigos e Outros Documentos

Files in This Item:
File Description SizeFormat 
2-s2.0-0031123068.pdf573.05 kBAdobe PDFView/Open


Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.