arXiv:cond-mat/0412620 · Physical Review B
Self-consistent Fermi surface renormalization of two coupled Luttinger liquids
Sascha Ledowski, Peter Kopietz, Álvaro Antônio Bandeira Ferraz
Abstract
Using functional renormalization group methods, we present a self-consistent calculation of the true Fermi momenta ${k}_{F}^{a}$ (antibonding band) and ${k}_{F}^{b}$ (bonding band) of two spinless interacting metallic chains coupled by small interchain hopping. In the regime where the system is a Luttinger liquid, we find that $\ensuremath{\Delta}={k}_{F}^{b}\ensuremath{-}{k}_{F}^{a}$ is self-consistently determined by $\ensuremath{\Delta}={\ensuremath{\Delta}}_{1}{[1+{g}_{0}^{2}\mathrm{ln}{({\ensuremath{\Lambda}}_{0}∕\ensuremath{\Delta})}^{2}]}^{\ensuremath{-}1}$, where ${g}_{0}$ is the dimensionless interchain backscattering interaction, ${\ensuremath{\Delta}}_{1}$ is the Hartree-Fock result for ${k}_{F}^{b}\ensuremath{-}{k}_{F}^{a}$, and ${\ensuremath{\Lambda}}_{0}⪢\ensuremath{\Delta}$ is an ultraviolet cutoff. For ${g}_{0}^{2}\mathrm{ln}{({\ensuremath{\Lambda}}_{0}∕{\ensuremath{\Delta}}_{1})}^{2}⪢1$ even weak interachain backscattering leads to a strong reduction of the distance between the Fermi momenta.