Exact and mean-field analysis of the role of Hubbard interactions on flux driven circular current in a quantum ring

Abstract

We investigate circular current in both ordered and disordered Hubbard quantum rings threaded by magnetic flux, employing exact diagonalization and the Hartree-Fock mean-field approach within the tight-binding framework. The influence of on-site and extended Hubbard interactions, disorder, and electron filling on the persistent current is systematically analyzed. To construct the full many-body Hamiltonian, we introduce a linear table formalism, which, to our knowledge, has been rarely used in this context. In ordered rings, the current decreases monotonically with increasing on-site repulsion, while the impact of the extended interaction depends strongly on the filling factor. At low filling, stronger extended interaction suppresses the current, whereas near half-filling, it enhances the current up to a critical ratio, half of the on-site strength, before reducing it. Disorder significantly modifies these behaviors, notably enhancing the current at less than quarter-filling with increasing extended interaction. The localization properties of eigenstates, examined via the inverse participation ratio, further support the crucial roles of filling and the interplay between on-site and extended interactions in governing persistent current.

arXiv comment12 pages, 8 figures (Accepted for publication in Journal of Physics: Condensed Matter)

References in corpus (26)

• Quantum rings for beginners: Energy spectra and persistent currents
• Persistent currents in normal metal rings
• Does the attractive Hubbard model support larger persistent currents than the repulsive one ?
• Electromagnetic coupling in tight-binding models for strongly correlated light and matter
• Coherent superposition of current flows in an Atomtronic Quantum Interference Device
• Persistent currents in rings of ultracold fermionic atoms
• Pressure dependent relaxation in the photo-excited Mott insulator ETF2TCNQ: Influence of hopping and correlations on quasiparticle recombination rates
• Entanglement of indistinguishable particles as a probe for quantum phase transitions in the extended Hubbard model
• Quantum correlations, entanglement spectrum and coherence of two-particle reduced density matrix in the Extended Hubbard Model
• Enhancement of persistent current in mesoscopic rings $&$ cylinders : shortest $&$ next possible shortest higher order hopping
• Magnetic Response of Interacting Electrons in a Fractal Network: A Mean Field Approach
• Strange behavior of persistent currents in small Hubbard rings
• A Hartree-Fock Study of Persistent Currents in Disordered Rings
• Analytical solution of open crystalline linear 1D tight-binding models
• Persistent current and Drude weight in mesoscopic rings
• Guide to Exact Diagonalization Study of Quantum Thermalization
• Biexciton in one-dimensional Mott insulators
• Persistent currents in ultracold gases
• Temperature-dependent periodicity of the persistent current in strongly interacting systems
• On the way to meet the experimental observation of persistent current in a mesoscopic cylinder: A mean field study
• Persistent Currents in Small, Imperfect Hubbard Rings
• Electrical analogue of one-dimensional and quasi-one-dimensional Aubry-André-Harper lattices
• The effect of the Coulomb interaction on the mesoscopic persistent current
• Circulating current in 1D Hubbard rings with long-range hopping: Comparison between exact diagonalization method and mean-field approach
• Temperature enhanced persistent currents and "${\varphi }_0/2$ periodicity"
• Exact diagonalization using hierarchical wave functions and calculation of topological entanglement entropy