NONTOPOLOGICAL THERMAL SOLITONS IN ISOTROPIC FERROMAGNETIC LATTICES

Article

关键词: HEISENBERG CHAIN;    STATISTICAL-MECHANICS;    ARBITRARY SPINS;    LOW-TEMPERATURE;    THERMODYNAMICS;    EXCITATIONS;    BEHAVIOR;    MODEL;   

DOI  :  10.1103/PhysRevB.52.9507

来源: SCIE

【 摘 要 】

The paper deals with the properties of thermally excited solitons of the isotropic spin-g ferromagnetic chain with nearest-neighbor logarithmic interactions. The exact statistical mechanics of the interacting soliton gas is developed for the general case (arbitrary S, temperature, and magnetic field). At low temperatures the model's thermodynamics coincides with that of the Heisenberg model. We present analytical approximations of the leading-order asymptotic behavior of the energy in three limiting cases: (a) zero field, low temperature, classical limit; (b) zero held, T --> 0, S finite (quantum limit); (c) zero field, high temperature, classical limit. Cases (a) and (c) are examples of a dense gas of [nontopological] solitons; results are in agreement with those obtained by the transfer integral method. Case (b) illustrates the behavior of a dilute, yet strongly interacting soliton gas; results for the thermodynamics are very close to (but not identical with) spin-wave and/or Bethe ansatz predictions.

【 授权许可】

Free