Self-consistent spin-wave theory of layered Heisenberg magnets

Article

关键词: MEAN-FIELD-THEORY;    LOW-TEMPERATURES;    SQUARE-LATTICE;    1/N EXPANSION;    PHASE-TRANSITIONS;    2 DIMENSIONS;    RANGE ORDER;    ANTIFERROMAGNETS;    MODEL;    FERROMAGNET;   

DOI  :  10.1103/PhysRevB.60.1082

来源: SCIE

【 摘 要 】

The versions of the self-consistent spin-wave theories (SSWT) of two-dimensional Heisenberg ferro- and antiferromagnets with a weak interlayer coupling and/or magnetic anisotropy, that are based on the nonlinear. Dyson-Maleev, Schwinger, and combined boson-pseudofermion representations, are analyzed. Analytical results for the temperature dependences of (sublattice) magnetization and the short-range order parameter, and the critical points are obtained. The influence of external magnetic field is considered. Fluctuation corrections to SSWT are calculated within a random-phase approximation which takes into account correctly leading and next-leading logarithmic singularities. These corrections are demonstrated to improve radically the agreement with experimental data on layered perovskites and other systems. Thus an account of these fluctuations provides a quantitative theory of layered magnets.

【 授权许可】

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