Ising and Gross-Neveu model in next-to-leading order

Article

关键词: FUNCTIONAL RENORMALIZATION-GROUP;    TOPOLOGICAL DIRAC SEMIMETAL;    EFFECTIVE AVERAGE ACTION;    INVAR TENSOR PACKAGE;    QUARK-MESON MODEL;    CRITICAL EXPONENTS;    FIELD-THEORY;    GRAPHENE SUPERLATTICES;    ARBITRARY DIMENSIONS;    DERIVATIVE EXPANSION;   

DOI  :  10.1103/PhysRevB.94.245102

来源: SCIE

【 摘 要 】

We study scalar and chiral fermionic models in next-to-leading order with the help of the functional renormalization group. Their critical behavior is of special interest in condensed-matter systems, in particular graphene. To derive the beta functions, we make extensive use of computer algebra. The resulting flow equations were solved with pseudospectral methods to guarantee high accuracy. New estimates of critical quantities for both the Ising and the Gross-Neveu model are provided. For the Ising model, the estimates agree with earlier renormalization-group studies of the same level of approximation. By contrast, the approximation for the Gross-Neveu model retains many more operators than all earlier studies. For two Dirac fermions, the results agree with both lattice and large-N-f calculations, but for a single flavor, different methods disagree quantitatively, and further studies are necessary.

【 授权许可】

Free