The current theoretical and experimental situations are reviewed for low-dimensional insulating systems with a low magnetic transition temperature Т_M and pronounced short-range magnetic order above this temperature. Both the standard and self-consistent spin-wave theories are shown to be insufficient to quantitatively describe the experimental data on these systems. Field-theoretical approaches taking into account the contribution of the spin-fluctuation excitations (neglected in the spin-wave theories) to the thermodynamic properties of ferro- and antiferromagnets are discussed.

PACS: 75.10.−b, 75.30.Ds, 75.40.Cx (all) DOI: 10.1070/PU2007v050n06ABEH006313 URL: https://ufn.ru/en/articles/2007/6/c/ 000249986100003 2-s2.0-35248830093 2007PhyU...50..613K Citation: Katanin A A, Irkhin V Yu "Magnetic order and spin fluctuations in low-dimensional insulating systems" Phys. Usp. 50 613–635 (2007) BibTexBibNote ® (generic)BibNote ® (RIS)MedlineRefWorks @article{Katanin:2007, author = {A. A. Katanin and V. Yu. Irkhin}, title = {Magnetic order and spin fluctuations in low-dimensional insulating systems}, publisher = {Physics-Uspekhi}, year = {2007}, journal = {Phys. Usp.}, volume = {50}, number = {6}, pages = {613-635}, url = {https://ufn.ru/en/articles/2007/6/c/}, doi = {10.1070/PU2007v050n06ABEH006313} } Оригинал: Катанин А А, Ирхин В Ю «Магнитный порядок и спиновые флуктуации в низкоразмерных системах» УФН 177 639–662 (2007); DOI: 10.3367/UFNr.0177.200706c.0639