2017/05/31 by Yuxuan Wang, Rahul Nandkishore, Rahul M. Nandkishore · 34 citations
Physics and Astronomy · #Condensed matter physics #Coulomb #Coupling (piping) #Degenerate energy levels #Hamiltonian (control theory) #Physics #Quantum and electron transport phenomena #Quantum many-body systems #Quantum mechanics #Renormalization #Renormalization group #Topological Materials and Phenomena #cond-mat.dis-nn #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.96.115130
published in Physical review. B./Physical review. B 96(11) (American Physical Society) · 13 pages, 4 figures, to match the published version
openalex publication_date 2017/09/18 · arxiv created 2017/09/27 · arxiv updated 2017/09/28 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
In nodal-line semimetals, Coulomb interactions and short-range correlated disorder are both marginal perturbations to the clean noninteracting Hamiltonian. We analyze their interplay using a weak-coupling renormalization group approach. In the clean case, the Coulomb interaction has been found to be marginally irrelevant, leading to Fermi liquid behavior. We extend the analysis to incorporate the effects of disorder. The nodal line structure gives rise to kinematical constraints similar to that for a two-dimensional Fermi surface, which plays a crucial role in the one-loop renormalization of the disorder couplings. For a twofold degenerate nodal loop (Weyl loop), we show that disorder flows to strong coupling along a unique fixed trajectory in the space of symmetry inequivalent disorder couplings. Along this fixed trajectory, all symmetry inequivalent disorder strengths become equal. For a fourfold degenerate nodal loop (Dirac loop), disorder also flows to strong coupling, however, the strengths of symmetry inequivalent disorder couplings remain different. We show that feedback from disorder reverses the sign of the beta function for the Coulomb interaction, causing the Coulomb interaction to flow to strong coupling as well. However, the Coulomb interaction flows to strong coupling asymptotically more slowly than disorder. Extrapolating our results to strong coupling, we conjecture that at low energies nodal line semimetals should be described by a noninteracting nonlinear sigma model. We discuss the relation of our results with possible many-body localization at zero temperatures in such materials.