2014/04/25 by Laura Classen, Michael M. Scherer, Carsten Honerkamp
Materials Science · Physics and Astronomy · #Graphene research and applications #Quantum and electron transport phenomena #Topological Materials and Phenomena #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.90.035122
published as Phys. Rev. B 90, 035122 (2014) · 9 pages, 5 figures
arxiv created 2014/04/25 · openalex publication_date 2014/07/17 · arxiv updated 2014/07/23 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We study the impact of electron-phonon interactions on the many-body instabilities of electrons on the honeycomb lattice and their interplay with repulsive local and nonlocal Coulomb interactions at charge neutrality. To that end, we consider in-plane optical phonon modes with wave vectors close to the \ensuremathΓ point as well as to the K,\phantom\rule0.16em0ex\ensuremath-K points and calculate the effective phonon-mediated electron-electron interaction by integrating out the phonon modes. Ordering tendencies are studied by means of a momentum-resolved functional renormalization-group approach allowing for an unbiased investigation of the appearing instabilities. In the case of an exclusive and supercritical phonon-mediated interaction, we find a Kekul'e and a nematic bond ordering tendency being favored over the s-wave superconducting state. The competition between the different phonon-induced orderings clearly shows a repulsive interaction between phonons at small- and large-wave-vector transfers. We further discuss the influence of phonon-mediated interactions on electronically driven instabilities induced by on-site, nearest-neighbor, and next-nearest-neighbor density-density interactions. We find an extension of the parameter regime of the spin-density-wave order going along with an increase of the critical scales where ordering occurs and a suppression of competing orders.