Persistent current and low-field magnetic susceptibility in one-dimensional mesoscopic rings: Effect of long-range hopping

Abstract

Persistent current and low-field magnetic susceptibility in single-channel normal metal rings threaded by a magnetic flux $\varphi$ are investigated within the tight-binding framework considering long-range hopping of electrons in the {\em shortest} path. The higher order hopping integrals try to reduce the effect of disorder by delocalizing the energy eigenstates, and accordingly, current amplitude in disordered rings becomes comparable to that of an ordered ring. Our study of low-field magnetic susceptibility predicts that the sign of persistent currents can be mentioned precisely in mesoscopic rings with fixed number of electrons, even in the presence of impurity in the rings. For perfect rings, low-field current shows only the diamagnetic sign irrespective of the total number of electrons $N_e$. On the other hand, in disordered rings it exhibits the diamagnetic and paramagnetic natures for the rings with odd and even $N_e$ respectively.

7 pages, 6 figures

References in corpus (6)

• Persistent Currents in 1D Disordered Rings of Interacting Electrons
• Does the attractive Hubbard model support larger persistent currents than the repulsive one ?
• Dynamic response of isolated Aharonov-Bohm rings coupled to an electromagnetic resonator
• Diamagnetic orbital response of mesoscopic silver rings
• Strange behavior of persistent currents in small Hubbard rings
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Cited by in corpus (4)

• Externally controlled local magnetic field in a conducting mesoscopic ring coupled to a quantum wire
• 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
• Persistent current in one-dimensional non-superconducting mesoscopic rings: effects of single hopping impurity, in-plane electric field and foreign atoms