Gauge dependenceof the order parameter anomalous dimension in the Ginzburg-Landau model and the critical fluctuations in superconductors

Дата и время публикации : 1998-08-10T16:41:51Z

Авторы публикации и институты :
F. S. Nogueira

Ссылка на журнал-издание: Europhys.Lett.45:612,1999
Коментарии к cтатье: EuroLaTex, 7 pages, 2 figures, reference updated; version to be published in Europhysics Letters
Первичная категория: cond-mat.supr-con

Все категории : cond-mat.supr-con

Краткий обзор статьи: The critical fluctuations of superconductors are discussed in a fixed dimension scaling suited to describe the type II regime. The gauge dependence of the anomalous dimension of the scalar field is stablished exactly from the Ward-Takahashi identities. Its fixed point value gives the $eta$ critical exponent and it is shown that $eta$ is gauge independent, as expected on physical grounds. In the scaling considered, $eta$ is found to be zero at 1-loop order, while $nuapprox 0.63$. This result is just the 1-loop values for the XY model obtained in the fixed dimension renormalization group approach. It is shown that this XY behavior holds at all orders. The result $eta=eta_{XY}$ should be contrasted with the negative values frequently reported in the literature.

Category: Physics