Low-energy excitations of a classical XY ferromagnetic chain in a transverse random field

WOS: 000080778700018Low-energy excitations of a classical XY ferromagnetic chain in a random sign transverse held are investigated using the coherent-potential approximation (CPA). Near the critical field strength, the dynamics of the system is similar to that of the high-held spin-glass chain system investigated earlier. The CPA reproduced the anomalous dispersion law and nontrivial dynamic and crossover exponents which were obtained by the renormalization-group technique. The CPA also predicts an explicit form of the scaling function. For symmetric and asymmetric distributions of the field, different dynamics and exponents are obtained. A brief analysis is given about the thermodynamics of the system