EXACT SOLUTION OF THE SOLITON-PHONON THEORY FOR THE CLASSICAL SINE-GORDON THERMODYNAMICS

The soliton-phonon theory of Johnson et al. and Timonen et al. for the classical sine-Gordon thermodynamics is exactly solved numerically to find its prediction for the free energy. The obtained free energy agrees with the exact transfer matrix method result only in the low reduced temperature or small effective coupling regime. It is thus concluded that the soliton-phonon theory is not exact.