The flow equation approach to the pairing instability problem
摘要
By means of the continuous unitary transformation similar to a general scheme of the Renormalization Group (RG) procedure we study the issue of symmetry breaking and pairing instability in the system of interacting fermions. Constructing a generalized version of the Bogoliubov transformation we show that formation of the fermion pairs and their superconductivity/superfluidity can appear at different temperatures. It is shown that strong quantum fluctuations can destroy the long-range order without breaking the fermion pairs which may still exist as incoherent and/or damped entities. Such unusual phase is characterized by a partial suppression of the density of states near the Fermi energy and by residual collective features like the sound-wave mode in the fermion pair spectrum.
引用
@article{arxiv.cond-mat/0610456,
title = {The flow equation approach to the pairing instability problem},
author = {T. Domanski and A. Donabidowicz},
journal= {arXiv preprint arXiv:cond-mat/0610456},
year = {2009}
}
备注
(7 pages, 4 figures) A brief summary of some recent works using the flow equation approach to the pairing instability problem