Magnetic response of interacting electrons in a fractal network: A mean-field approach

Abstract

The Hubbard model on a Sierpinski gasket fractal is carefully examined within a Hartree-Fock mean field approach. We examine the influence of a magnetic flux threading the gasket on its ground state energy, persistent current and the Drude weight. Both an isotropic gasket and its anisotropic counterpart have been examined. The variance in the patterns of the calculated physical quantities are discussed for two situations, viz, at half-filling and when the 'band' is less than half-filled. The phase reversal of the persistent currents and the change of the Drude weight as a function of the Hubbard interaction are found to exhibit interesting patterns that have so far remained unaddressed.

Circulating persistent current and induced magnetic field in a fractal network

“…This unique feature is observed only when leads are connected on either sides of the bases of SPG e.g., at positions 1 and 3 for this particular generation of the fractal. Analogous feature is also observed when leads are coupled to the sites (1,15) and (1,22) of 2nd and 3rd generations, respectively, and even valid for any higher generation. This mirror symmetry gets disturbed when the drain lead is connected elsewhere.…”

Possible polaron formation of zigzag graphene nano-ribbon in the presence of Rashba spin–orbit coupling

“…Accordingly the on-site energy is spin-dependent and corresponds to the density of opposite spin [5][6][7][8][9][10][35][36][37]. The decoupled Hamiltonian of spin up and down states should be solved in a self-consistent manner for a starting point.…”

Conformation dependent magnetotransport in a single handed helical geometry

“…Using a tight-binding (TB) framework we describe the model and compute all the numerical results within a Hartree-Fock (HF) mean field level [29][30][31][32] . The results are impressive.…”