Year: 2010
Type: article
Abstract: We formulate a momentum-shell renormalization-group (RG) procedure that can be used in theories containing both bosons and fermions with a Fermi surface. We focus on boson-fermion couplings that are nearly forward scattering, i.e., involving small momentum transfer $(\stackrel{P\vec}{q}\ensuremath{\approx}0)$ for the fermions. Special consideration is given to phase space constraints that result from the conservation of momentum and the imposition of ultraviolet cutoffs. For problems where the energy and momentum scale similarly (dynamic exponent $z=1$), we show that more than one formalism can be used and they give equivalent results. When the energy and momentum must scale differently $(z\ensuremath{\ne}1)$, the procedures available are more limited but a consistent RG scheme can still be formulated. The approach is applicable to a variety of problems, such as itinerant-electron magnets and gauge fields interacting with fermions.
Source: Physical Review B
Authors: Seiji J. Yamamoto, Qimiao Si
Institution: Rice University
Language: English
Subfield: Condensed Matter Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W1974470143