Field theoretic functional renormalization group study of the antiferromagnetic quantum critical metal in two dimensions

To describe the full low-energy theory of metals that include all gapless modes around the Fermi surface, generalized notions of renormalizable field theory and scale invariance are needed due to the presence of intrinsic scales (Fermi momentum). In this work, we study the universal low-energy physics of the two-dimensional antiferromagnetic quantum critical metal through a novel field-theoretic functional renormalization group formalism. In this theory, critical spin fluctuations destroy the coherence of single-particle excitations near the hot spots on the Fermi surface, and at the same time, they provide the attractive glue that results in the formation of Cooper pairs. We discuss how the interplay between these pair-breaking and pair-forming effects of spin fluctuations controls the universal non-Fermi liquid behaviour of the normal state that is eventually cut off by a superconducting instability in the low energy limit.

Reference : F. Borges, A. Borissov, A. Singh, A. Schlief, S.-S. Lee, arXiv:2208.00730.