Enhancement of persistent current in mesoscopic rings $&$ cylinders : shortest $&$ next possible shortest higher order hopping

Abstract

We present a detailed study of persistent current and low-field magnetic susceptibility in single isolated normal metal mesoscopic rings and cylinders in the tight-binding model with higher order hopping integral in the Hamiltonian. Our exact calculations show that order of magnitude enhancement of persistent current takes place even in presence of disorder if we include higher order hopping integral in the Hamiltonian. In strictly one-channel mesoscopic rings the sign of the low-field currents can be predicted exactly even in presence of impurity. We observe that perfect rings with both odd and even number of electrons support only diamagnetic currents. On the other hand in the disordered rings, irrespective of realization of the disordered configurations of the ring, we always get diamagnetic currents with odd number of electrons and paramagnetic currents with even number of electrons. In mesoscopic cylinders the sign of the low-field currents can't be predicted exactly since it strongly depends on the total number of electrons, $N_e$, and also on the disordered configurations of the system. From the variation of persistent current amplitude with system size for constant electron density, we conclude that the enhancement of persistent current due to additional higher order hopping integrals are visible only in the mesoscopic regime.

12 pages, 12 figures

References in corpus (5)

• Persistent Currents in 1D Disordered Rings of Interacting Electrons
• Does the attractive Hubbard model support larger persistent currents than the repulsive one ?
• Diamagnetic orbital response of mesoscopic silver rings
• Strange behavior of persistent currents in small Hubbard rings
• On the role of electron correlation and disorder on persistent currents in isolated one-dimensional rings

Cited by in corpus (12)

• Magnetic Response in Mesoscopic Hubbard Rings: A Mean Field Study
• Externally controlled local magnetic field in a conducting mesoscopic ring coupled to a quantum wire
• On the way to meet the experimental observation of persistent current in a mesoscopic cylinder: A mean field study
• Persistent charge and spin currents in a quantum ring using Green's function technique: Interplay between magnetic flux and spin-orbit interactions
• Circulating current in 1D Hubbard rings with long-range hopping: Comparison between exact diagonalization method and mean-field approach
• A renormalization group study of persistent current in a quasiperiodic ring
• Unconventional localization phenomena in a spatially non-uniform disordered material
• Fractional periodicity and magnetism of extended quantum rings
• Unconventional low-field magnetic response of a diffusive ring with spin-orbit coupling
• Conformation dependent magnetotransport in a single handed helical geometry
• Persistent current in one-dimensional non-superconducting mesoscopic rings: effects of single hopping impurity, in-plane electric field and foreign atoms
• Exact and mean-field analysis of the role of Hubbard interactions on flux driven circular current in a quantum ring