2021/04/19 by Maksim Ulybyshev, Savvas Zafeiropoulos, Ulybyshev, Maksim +5 · 1 citation
Physics and Astronomy · Mathematics · #Theoretical and Computational Physics #Markov Chains and Monte Carlo Methods #Mathematical Approximation and Integration
paper · pdf · doi:10.48550/arxiv.2104.09655
We report results of large-scale quantum Monte Carlo (QMC) simulations of\ngraphene. Using cutting-edge algorithmic improvements, we are able to consider\nspatial volumes, corresponding to 20808 electrons, that allow us to access\nenergy scales of direct relevance to experiments. Using constrained random\nphase approximation (cRPA) estimates of short-ranged interactions combined with\na Coulomb tail, we are able to successfully confront numerical and experimental\nestimates of the Fermi velocity renormalization. These results and their\ncomparison with perturbation theory not only show the non-Fermi liquid\ncharacter of graphene, but also prove the importance of lattice-scale physics\nand higher-order perturbative corrections beyond RPA for the quantitative\ndescription of the experimental data for the Fermi velocity renormalization in\nsuspended graphene.\n