Equations of motion method for triplet excitation operators in graphene

Abstract

Particle-hole continuum in Dirac sea of graphene has a unique window underneath,which in principle leaves a room for bound state formation in the triplet particle hole channel [Phys. Rev. Lett. {\bf 89}, 016402 (2002)]. In this work, we construct appropriate triplet particle-hole operators, and using a repulsive Hubbard type effective interaction, we employ equations of motions to derive approximate eigen-value equation for such triplet operators. While the secular equation for the spin density fluctuations gives rise to an equation which is second order in the strength of the short range interaction, the explicit construction of the triplet operators obtained here shows that in terms of these operators, the second order can be factorized to two first order equations, one of which gives rise to a solution below the particle-hole continuum of Dirac electrons in undoped graphene.

3 figures; http://iopscience.iop.org/0953-8984/labtalk-article/48600

References in corpus (15)

• The electronic properties of graphene
• Dielectric function, screening, and plasmons in 2D graphene
• Dynamical polarization of graphene at finite doping
• Quantum spin-liquid emerging in two-dimensional correlated Dirac fermions
• Strength of effective Coulomb interactions in graphene and graphite
• First direct observation of Dirac fermions in graphite
• Scanning Tunneling Spectroscopy of Graphene on Graphite
• Is graphene in vacuum an insulator?
• Two-dimensional Mott-Hubbard electrons in an artificial honeycomb lattice
• Lattice field theory simulations of graphene
• Dynamical Mean Field Study of The Dirac Liquid
• The fate of the resonating valence bond in graphene
• Variational RVB wave function for the spin-1/2 Heisenberg Model on honeycomb lattice
• Theory of Neutron Scattering for Gapless Neutral Spin-1 Collective Mode in Graphite
• Neutral triplet Collective Mode as a new decay channel in Graphite

Cited by in corpus (8)

• Polarization tensor for tilted Dirac fermion materials: Covariance in deformed Minkowski spacetime
• Sound of Fermi arcs
• Electromagnetic modes from Stoner enhancement
• Electronic properties of the Dirac and Weyl systems with first- and higher-order dispersion in non-Fermi-liquid picture
• Electronic properties and polaronic dynamics of semi-Dirac system within ladder approximation
• Collective excitations and the nature of Mott transition in undoped gapped graphene
• Composite polaron formed on surface of two-dimensional lattice system in weak coupling regime
• Optical conductivity of a Dirac-Fermi liquid