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】
Free