Elementary excitations for the integrable spin-SHeisenberg chain with an impurity spin
Yosuke Morita, Sei-ichiro Suga, A. Okiji
Elementary excitations for the integrable spin-S antiferromagnetic Heisenberg chain with an impurity spin are investigated by using the Bethe ansatz solution. Dressed holes are introduced in order to describe the elementary excitation. The characteristic energy dependence of the spectral density for the elementary excitation at zero temperature is discussed in connection with behaviour patterns of physical quantities. We extend our calculation for the elementary excitation to the case of finite temperatures, applying the method developed by Yang and Yang for one-dimensional interacting boson systems. At finite temperatures, in the case where , the spectral density shows a divergence property at zero excitation energy irrespective of the temperature, whereas in the case where , the peak structure develops in the low-energy region as the temperature is decreased.
Journal of Physics Condensed Matter•Mar 11, 1996•2 citations