• 文献标题:   Antiferromagnetism and competing charge instabilities of electrons in strained graphene from Coulomb interactions
  • 文献类型:   Article
  • 作  者:   DE LA PENA DS, LICHTENSTEIN J, HONERKAMP C, SCHERER MM
  • 作者关键词:  
  • 出版物名称:   PHYSICAL REVIEW B
  • ISSN:   2469-9950 EI 2469-9969
  • 通讯作者地址:   Rhein Westfal TH Aachen
  • 被引频次:   9
  • DOI:   10.1103/PhysRevB.96.205155
  • 出版年:   2017

▎ 摘  要

We study the quantum many-body ground states of electrons on the half-filled honeycomb lattice with short- and long-ranged density-density interactions as a model for graphene. To this end, we employ the recently developed truncated-unity functional renormalization group (TU-fRG) approach which allows for a high resolution of the interaction vertex' wave vector dependence. We connect to previous lattice quantum Monte Carlo (QMC) results which predict a stabilization of the semimetallic phase for realistic ab initio interaction parameters and confirm that the application of a finite biaxial strain can induce a quantum phase transition towards an ordered ground state. In contrast to lattice QMC simulations, the TU-fRG is not limited in the choice of tight-binding and interaction parameters to avoid the occurrence of a sign problem. Therefore, we also investigate a range of parameters relevant to the realistic graphene material which are not accessible by numerically exact methods. Although a plethora of charge-density waves arises under medium-range interactions, we find the antiferromagnetic spin-density wave to be the prevailing instability for long-range interactions. We further explore the impact of an extended tight-binding Hamiltonian with second-nearest-neighbor hopping and a finite chemical potential for a more accurate description of the band structure of graphene's p(z) electrons.