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We compare the magnetic field at the center of and the self-magnetic flux through a current-carrying circular loop, with those obtained for current-carrying polygons with the same perimeter. As the magnetic field diverges at the position of…

Physics Education · Physics 2007-05-23 J. P. Silva , A. J. Silvestre

The conduction band electron states of laterally-coupled semiconductor quantum rings are studied within the frame of the effective mass envelope function theory. We consider the effect of axial and in-plane magnetic fields for several…

Mesoscale and Nanoscale Physics · Physics 2015-06-25 J. Planelles , F. Rajadell , J. I. Climente , M. Royo , J. L. Movilla

A correct general formula for the spin current through an interacting quantum dot coupled to ferromagnetic leads with magnetization at an arbitrary angle $\theta$ is derived within the framework of the Keldysh formalism. Under asymmetric…

Mesoscale and Nanoscale Physics · Physics 2009-03-18 Hao Zhang , Guang-Ming Zhang , Lu Yu

The main objective of this work is to investigate theoretically how tilting of an easy axis of a single-molecule magnet (SMM) from the orientation collinear with magnetic moments of the leads affects the switching process induced by current…

Mesoscale and Nanoscale Physics · Physics 2016-08-14 Maciej Misiorny , Józef Barnas

We put forward a new approach based on Green's function formalism to evaluate precisely persistent charge and spin currents in an Aharonov-Bohm ring subjected to Rashba and Dresselhaus spin-orbit interactions. Unlike conventional methods…

Mesoscale and Nanoscale Physics · Physics 2014-08-19 Santanu K. Maiti , Moumita Dey , S. N. Karmakar

We study theoretically the linear conductance of a quantum dot connected to ferromagnetic leads. The dot level is split due to a non-collinear magnetic field or intrinsic magnetization. The system is studied in the non-interacting…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 Jonas N. Pedersen , Jesper Q. Thomassen , Karsten Flensberg

We study the generation of electronic ring currents in the presence of nonadiabatic coupling using circularly polarized light. For this, we introduce a solvable model consisting of an electron and a nucleus rotating around a common center…

Chemical Physics · Physics 2021-02-03 Krishna R. Nandipati , Oriol Vendrell

We consider circular currents in molecular wires with loop substructures studied within simple tight-binding models. Previous studies of this issue have focused on specific molecular structures. Here we address several general issues. First…

Mesoscale and Nanoscale Physics · Physics 2010-12-03 Dhurba Rai , Oded Hod , Abraham Nitzan

A time-dependent electric field gives rise to a stationary non-equilibrium current I^{(2)} around a mesoscopic metal ring threaded by a magnetic flux. We show that this current, which is proportional to the intensity of the field, is…

Mesoscale and Nanoscale Physics · Physics 2009-10-30 Peter Kopietz , Axel Voelker

We report spin-dependent quantum coherent oscillations (ringing) and beats of the total and spin currents flowing through a quantum dot with Zeeman split levels. The spin dependent transport is calculated via nonequilibrium Green function…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 Fabricio M. Souza

With the rotation of charge in a circular path current-loop is generated. This results in the production of magnetic fields in a charged body. This self (internal) magnetic field is treated here with five different radii of electron. Closed…

General Physics · Physics 2010-09-17 S. Ghosh , M. R. Devi , A. Choudhury , J. K. Sarma

A single-mode microcavity with an embedded Aharonov-Bohm quantum ring, which is pierced by a magnetic flux and subjected to a lateral electric field, is studied theoretically. It is shown that external electric and magnetic fields provide…

Mesoscale and Nanoscale Physics · Physics 2014-09-02 A. M. Alexeev , I. A. Shelykh , M. E. Portnoi

The ground states of few electrons confined in two vertically coupled quantum rings in the presence of an external magnetic field are studied systematically within the current spin-density functional theory. Electron-electron interactions…

Mesoscale and Nanoscale Physics · Physics 2009-10-05 L. K. Castelano , G. -Q. Hai , B. Partoens , F. M. Peeters

We consider a quantum $LC$ circuit under a constant magnetic flux $f$, and derive a discretized form of the Schr\"odinger equation, which is equivalent to introducing a {\em potential} $V(\phi,f)$ in the pseudo-flux $\phi$-representation,…

Mesoscale and Nanoscale Physics · Physics 2009-07-09 Constantino A. Utreras Díaz , David Laroze

We demonstrate that the combined effect of a spatially periodic potential, lateral confinement and spin-orbit interaction gives rise to a quantum ratchet mechanism for spin-polarized currents in two-dimensional coherent conductors. Upon…

Mesoscale and Nanoscale Physics · Physics 2007-11-07 Matthias Scheid , Andreas Pfund , Dario Bercioux , Klaus Richter

The inverse current, i.e., induced current is opposite to applied force, has recentlybeen found in a classical one-dimensional interacting Hamiltonian system [Phys. Rev.Lett. 124, 110607 (2020)]. In this paper, we show that inverse current…

Quantum Physics · Physics 2022-01-12 Yanchao Zhang , Zhenzhen Xie

We discuss the diamagnetism induced in an isolated quantum Hall bilayer with total filling factor one by an in-plane magnetic field. This is a signature of counterflow superfluidity in these systems. We calculate magnetically induced…

Mesoscale and Nanoscale Physics · Physics 2012-04-27 P. R. Eastham , N. R. Cooper , D. K. K. Lee

The time-dependent non-crossing approximation is used to study the transient current in a single electron transistor attached asymmetrically to two leads following a sudden change in the energy of the dot level. We show that for asymmetric…

Strongly Correlated Electrons · Physics 2015-05-13 A. Goker , B. A. Friedman , P. Nordlander

NOR gate response in a double quantum ring, where each ring is threaded by a magnetic flux $\phi$, is investigated. The double quantum ring is sandwiched symmetrically between two semi-infinite one-dimensional metallic electrodes and two…

Mesoscale and Nanoscale Physics · Physics 2009-11-20 Santanu K. Maiti

We propose an entanglement mechanism of nuclear spins in quantum dots driven by the electric current accompanied by the spin flip. This situation is relevant to a leakage current in spin-blocked regions where electrons cannot be transported…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 M. Eto , T. Ashiwa , M. Murata