Related papers: Persistent currents in coupled mesoscopic rings
We formalize the parity effect of a multichannel ring coupled to a side branch using the tight binding model. We find that the tight binding model gives slightly different result from the continuum model. We also show that some states of…
The transfer of charge between different regions of a phase-coherent mesoscopic sample is investigated. Charge transfer from a side branch quantum dot into a ring changes the persistent current through a sequence of plateaus of diamagnetic…
We investigate the stability of persistent currents in superfluid fermionic gases confined to a ring geometry. Our study, conducted at zero temperature using time-dependent density functional theory, cover interaction regimes from strong…
We study the current magnification effect and associated circulating currents in mesoscopic systems at equilibrium. Earlier studies have revealed that in the presence of transport current(non-equilibrium situation), circulating currents can…
Quantum coherence of electrons interacting via the magnetostatic coupling and confined to a mesoscopic cylinder is discussed. The electromagnetic response of a system is studied. It is shown that the electromagnetic kernel has finite low…
The persistent current in small isolated rings enclosing magnetic flux is the current circulating in equilibrium in the absence of an external excitation. While initially studied in superconducting and normal metals, recently, atomic…
The persistent current $I$ in integrable models of multichannel rings with both short- and long-ranged interactions is investigated. $I$ is found to oscillate in sign and increase in magnitude with increasing interaction strength due to…
We study theoretically the contribution of fluctuating Cooper pairs to the persistent current in superconducting rings threaded by a magnetic flux. For sufficiently small rings, in which the coherence length $\xi$ exceeds the radius $R$,…
The effect of the Coulomb-interaction on persistent currents in disordered mesoscopic metal rings threaded by a magnetic flux $\phi$ is studied numerically. We use the simplest form of ``self-consistent'' Hartree theory, where the spatial…
An interacting quantum dot inserted in a mesoscopic ring is investigated. A variational ansatz is employed to describe the ground state of the system in the presence of the Aharonov-Bohm flux. It is shown that, for even number of electrons…
We consider a bidimensional discrete annular cavity with surface roughness (SR) threaded by a magnetic flux. In the ballistic regime and at half filling, localized border-states show up. These border states contribute coherentely to the…
In this paper we analyze the possibility of persistent currents of a two-species bosonic mixture in the one-dimensional ring geometry. We extend the arguments used by Bloch to obtain a criterion for the stability of persistent currents for…
Current enhancement- a novel quantum phenomena is found to occur in a mesoscopic hybrid ring at equilibrium. The hybrid system is described by a ring with bubble which is in turn coupled to a reservoir. In the system the ring encloses a…
The persistent current in strictly one-dimensional Dirac systems is investigated within two different models, defined in the continuum and on a lattice, respectively. The object of the study is the effect of a single magnetic or nonmagnetic…
We have done a study with small, imperfect Hubbard rings with exact diagonalization. The results for few-electron rings show, that the imperfection, whether localized or not, nearly always decrease, but can also \emph{increase} the…
Using the Anderson model in the Kondo regime, we calculate the persistent current j in a ring with an embedded quantum dot (QD) as a function of the Aharonov-Bohm flux Phi for different ring length L, temperature T and broadening of the…
It is shown that in a structure consisting of a superconducting ring-shaped electrode overlapped by a normal metal contact through a thin oxide barrier, measurements of the tunnel current in magnetic field can probe persistent currents in…
The remarkably large persistent currents that are observed in disordered micron-scale gold rings at low temperatures have recently been explained in a theory of non-interacting electrons scattered by crystal grain boundaries. The present…
The persistent current, i.e. the equilibrium direct electric current circulating in realistic rings, some authors interpreted as dissipationless in spite of non-zero resistance of the rings, whereas the other one suppose that this current…
We calculate the average persistent current in a mesoscopic metal ring threaded by a magnetic flux in the diffusive regime. It is shown that the classical electromagnetic energy leads to a {\it{universal}} average current of the order of $…