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Equations-of-motion method for triplet excitation operators in graphene

Jafari, S. A ; Sharif University of Technology | 2012

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  1. Type of Document: Article
  2. DOI: 10.1088/0953-8984/24/9/095601
  3. Publisher: 2012
  4. Abstract:
  5. The particlehole continuum in the Dirac sea of graphene has a unique window underneath, which in principle leaves room for bound state formation in the triplet particlehole channel (Baskaran and Jafari 2002 Phys. Rev. Lett. 89 016402). In this work, we construct appropriate triplet particlehole operators and, using a repulsive Hubbard-type effective interaction, we employ equations of motion to derive approximate eigenvalue equations 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 equation can be factorized to two first-order equations, one of which gives rise to a solution below the particlehole continuum of Dirac electrons in undoped graphene
  6. Keywords:
  7. Bound state ; Effective interactions ; Eigenvalue equations ; Explicit constructions ; First order equations ; Second orders ; Second-order equation ; Secular equations ; Short range interactions ; Spin-density fluctuations ; Triplet excitation ; Eigenvalues and eigenfunctions ; Equations of motion ; Excited states ; Graphene ; Chemistry ; Neutron ; Algorithms ; Computer Simulation ; Electrons ; Graphite ; Neutrons
  8. Source: Journal of Physics Condensed Matter ; Volume 24, Issue 9 , February , 2012 ; 09538984 (ISSN)
  9. URL: http://iopscience.iop.org/article/10.1088/0953-8984/24/9/095601/meta;jsessionid=FEE9DF965F9ADDA382C2B097B7A9081A.c2.iopscience.cld.iop.org