Circulating current in 1D Hubbard rings with long-range hopping: Comparison between exact diagonalization method and mean-field approach

Article Type

Research Article

Publication Title

Physica E: Low-Dimensional Systems and Nanostructures

Abstract

The interplay between Hubbard interaction, long-range hopping and disorder on persistent current in a mesoscopic one-dimensional conducting ring threaded by a magnetic flux φ is analyzed in detail. Two different methods, exact numerical diagonalization and Hartree-Fock mean field theory, are used to obtain numerical results from the many-body Hamiltonian. The current in a disordered ring gets enhanced as a result of electronic correlation and it becomes more significant when contributions from higher order hoppings, even if they are too small compared to nearest-neighbor hopping, are taken into account. Certainly this can be an interesting observation in the era of long-standing controversy between theoretical and experimental results of persistent current amplitudes. Along with these we also find half-flux quantum periodic current for some typical electron fillings and kink-like structures at different magnetic fluxes apart from φ=0 and ±φ0/2. The scaling behavior of current is also discussed for the sake of completeness of our present analysis.

First Page

118

Last Page

134

DOI

10.1016/j.physe.2016.05.042

Publication Date

10-1-2016

Comments

Open Access; Green Open Access

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