Dynamics of random one-dimensional +/- J systems

Faculty Science Year: 2003
Type of Publication: Article Pages: 1229-1243
Authors: DOI: 10.1023/B:CJOP.0000010587.55971.35
Journal: CZECHOSLOVAK JOURNAL OF PHYSICS INST PHYSICS ACAD SCI CZECH REPUBLIC Volume: 53
Research Area: Physics ISSN ISI:000188507200009
Keywords : two-state Potts spin, +/- J model, linear response theory, relaxation times, specific heat    
Abstract:
Finite chains of a two-state random Potts spin model with periodic boundary conditions are studied within Glauber dynamics. The spin exchange is assumed random with frustration between ferro and antiferromagnetic values (+/-J). Time-dependent fluctuations are induced by periodic temperature oscillations. Master type differential equations for spin correlation functions are solved within linear response theory. The spectrum of relaxation times are calculated at different temperatures. The +/-J Potts glass chains undergo a zero temperature phase transition. The barriers against inversion of the spin chain take only two values; 0 and 2 \textbackslash{}J\textbackslash{}. The temperature behaviour of specific heat is characterized by rounded peaks. The frequency dependence displays two plateaus for the real part of specific heat and two corresponding peaks for the imaginary part. The dynamic specific heat is not affected by the longest relaxing mode like susceptibility. The time separation of the modes is demonstrated by the Cole-Cole plots.
   
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