Stability of Dirac Liquids with Strong Coulomb Interaction
2017 (English)In: Physical Review Letters, ISSN 0031-9007, E-ISSN 1079-7114, Vol. 118, no 2, 026403Article in journal (Refereed) Published
We develop and apply the diagrammatic Monte Carlo technique to address the problem of the stability of the Dirac liquid state (in a graphene-type system) against the strong long-range part of the Coulomb interaction. So far, all attempts to deal with this problem in the field-theoretical framework were limited either to perturbative or random phase approximation and functional renormalization group treatments, with diametrically opposite conclusions. Our calculations aim at the approximation-free solution with controlled accuracy by computing vertex corrections from higher-order skeleton diagrams and establishing the renormalization group flow of the effective Coulomb coupling constant. We unambiguously show that with increasing the system size L (up to ln(L)∼40), the coupling constant always flows towards zero; i.e., the two-dimensional Dirac liquid is an asymptotically free T=0 state with divergent Fermi velocity.
Place, publisher, year, edition, pages
American Physical Society, 2017. Vol. 118, no 2, 026403
Approximation algorithms, Coulomb interactions, Monte Carlo methods, Statistical mechanics, Coulomb couplings, Coupling constants, Functional renormalization group, Monte Carlo techniques, Random phase approximations, Renormalization group, Theoretical framework, Vertex correction, Liquids
IdentifiersURN: urn:nbn:se:kth:diva-202223DOI: 10.1103/PhysRevLett.118.026403ISI: 000391927700007ScopusID: 2-s2.0-85010399644OAI: oai:DiVA.org:kth-202223DiVA: diva2:1082998
Funding text: This work was supported by the Simons Collaboration on the Many Electron Problem, the National Science Foundation under the Grant No. PHY-1314735, the MURI Program New Quantum Phases of Matter from AFOSR, the Stiftelsen Olle Engkvist Byggmstare Foundation, and the Swedish Research Council Grant No. 642-2013-7837. QC 201703202017-03-202017-03-202017-03-20Bibliographically approved