Now showing items 1-6 of 6

    • Hubbard model In Square Lattices: A Mean-field Hartree-fock Approach 

      Yönaç, Muhammed (Bilkent University, 2005)
      This thesis is mainly an effort to reproduce the well-known results that HartreeFock approximation gives for the Hubbard Model in two dimensions. As the area of application magnetic phases in the finite-size square ...
    • Quantum correlations of spin-1 atoms in an optical lattice 

      Öztop, B.; Oktel, M. Ö.; Müstecaplioǧlu, Ö. E. (Institute of Physics Publishing, 2009)
      In this work, we investigate the system of cold spin-1 atoms in a one dimensional optical lattice in relation with squeezing and entanglement. By using the corresponding Bose-Hubbard Hamiltonian, both superfluid and ...
    • Quantum entanglement of spin-1 bosons with coupled ground states in optical lattices 

      Öztop, B.; Oktel, M. Ö.; Müstecapliolu, Ö. E.; You, L. (IOP Institute of Physics Publishing, 2009)
      We examine particle entanglement, characterized by pseudo-spin squeezing, of spin-1 bosonic atoms with coupled ground states in a one-dimensional optical lattice. Both the superfluid and Mott-insulator phases are investigated ...
    • Size-dependent alternation of magnetoresistive properties in atomic chains 

      Durgun, Engin; Senger, R. T.; Mehrez, H.; Sevinçli, H.; Çıracı, Salim (American Institute of Physics, 2006)
      Spin-polarized electronic and transport properties of carbon atomic chains are investigated when they are capped with magnetic transition-metal (TM) atoms like Cr or Co. The magnetic ground state of the TM-C n-TM chains ...
    • Spin confinement in the superlattices of graphene ribbons 

      Topsakal, M.; Sevinçli, H.; Çıracı, Salim (AIP Publishing, 2008)
      Based on first-principles calculations, we showed that repeated heterostructures of zigzag graphene nanoribbons of different widths form multiple quantum well structures. Edge states of specific spin directions can be ...
    • Spintronic properties of zigzag-edged triangular graphene flakes 

      Şahin, H.; Senger, R. T.; Çıracı, Salim (AIP Publishing LLC, 2010)
      We investigate quantum transport properties of triangular graphene flakes with zigzag edges by using first principles calculations. Triangular graphene flakes have large magnetic moments which vary with the number of ...