A ferromagnetic chain in a random weak field
Articles > Article · 1996
Authors: İbrahim AVGIN
JOURNAL OF PHYSICS-CONDENSED MATTER, Journal Indexed in SCI Expanded, International, 1996, vol 8, pp 8379-8383
DOI: 10.1088/0953-8984/8/43/028
Summary
The harmonic magnon modes in a Heisenberg ferromagnetic chain in a random weak field are studied. The Lyapunov exponent for the uniform (Ic = 0) mode is computed using the coherent potential approximation (CPA) in the weak-disorder limit. The CPA results are compared with the numerical and weak-disorder expansions of various random systems. We have found that the inverse localization length and the integrated density of states have anomalous power law behaviour as reported earlier. The CPA also reproduces the dispersion law for the same system, calculated by Pimentel and Stinchcombe using the real space renormalization scaling technique. A brief comment is also made for the uniform weak-field case.