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Paper   IPM / P / 13873
School of Physics
Title:   Excitation spectrum of correlated Dirac fermions
Author(s):
 1 Z. Jalali 2 S.A. Jafari
Status:   Published
Journal: J. Phys.: Conf. Series
Vol.:  603
Year:  2015
Pages:   012005
Supported by:  IPM
Abstract:
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 doublons can 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.