Critical thermodynamics of two-dimensional N-vector cubic model in the five-loop approximation

• Дата: 2005
• Автори: Calabrese, P., Orlov, E.V., Pakhnin, D.V., Sokolov, A.I.
• Формат: Стаття
• Мова: English
• Опубліковано: Інститут фізики конденсованих систем НАН України 2005
• Назва видання: Condensed Matter Physics
• Онлайн доступ: http://dspace.nbuv.gov.ua/handle/123456789/119483
• Назва журналу: Digital Library of Periodicals of National Academy of Sciences of Ukraine
• Цитувати: Critical thermodynamics of two-dimensional N-vector cubic model in the five-loop approximation / P. Calabrese, E.V. Orlov, D.V. Pakhnin, A.I. Sokolov // Condensed Matter Physics. — 2005. — Т. 8, № 1(41). — С. 193–211. — Бібліогр.: 31 назв. — англ.

The critical behavior of the two-dimensional N-vector cubic model is studied within the field-theoretical renormalization-group (RG) approach. The β functions and critical exponents are calculated in the five-loop approximation, RG series obtained are resummed using Pade-Borel-Leroy and ´ conformal mapping techniques. It is found that for N = 2 the continuous line of fixed points is well reproduced by the resummed RG series and an account for the five-loop terms makes the lines of zeros of both β functions closer to each other. For N > 3 the five-loop contributions are shown to shift the cubic fixed point, given by the four-loop approximation, towards the Ising fixed point. This confirms the idea that the existence of the cubic fixed point in two dimensions under N >2 is an artifact of the perturbative analysis. In the case N = 0 the results obtained are compatible with the conclusion that the impure critical behavior is controlled by the Ising fixed point.