Excitation spectrum of correlated Dirac fermions

International Workshop on Dirac Electrons in Solids 2015

Jalali, Z.^1 ; Jafari, S.A.^1,2,3

Department of Physics, Sharif University of Technology, Tehran

11155-9161, Iran^1

Center of Excellence for Complex Systems and Condensed Matter (CSCM), Sharif University of Technology, Tehran

1458889694, Iran^2

School of Physics, Institute for Research in Fundamental Sciences (IPM), Tehran

19395-5531, Iran^3

关键词: Composition rule;    Dirac fermions;    Excitation spectrum;    Finite density;    Honeycomb lattices;    Optical conductivity measurements;    Particle methods;    Strong electronic correlations;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/603/1/012005/pdf
DOI  :  10.1088/1742-6596/603/1/012005

来源: IOP

【 摘 要 】

Motivated by the puzzling optical conductivity measurements in graphene, we speculate on the possible role of strong electronic correlations on the two-dimensional Dirac fermions. In this work we employ the slave-particle method to study the excitations of the Hubbard model on honeycomb lattice, away from half-filling. Since the ratio U/t ≈ 3.3 in graphene is not infinite, double occupancy is not entirely prohibited and hence a finite density of doublonscan be generated. We therefore extend the Ioff-Larkin composition rule to include a finite density of doublons. We then investigate the role played by each of these auxiliary particles in the optical absorption of strongly correlated Dirac fermions.