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The electronic transport of a noninteracting quantum ring side-coupled to a quantum wire is studied via a single-band tunneling tight-binding Hamiltonian. We found that the system develops an oscillating band with antiresonances and…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 P. A. Orellana , M. L. Ladron de Guevara , M. Pacheco , A. Latge

We study the current flow through semiconductor quantum rings. In high magnetic field the current is usually injected to the arm of the ring preferred by classical magnetic forces. However, for narrow magnetic field intervals that appear…

Mesoscale and Nanoscale Physics · Physics 2010-11-09 M. R. Poniedziałek , B. Szafran

We study the quantum backflow problem of a relativistic charged Dirac fermion constrained to move on a ring of radius $R$. Using the relativistic current operator we compute the probability flux through a generic time interval to show…

Quantum Physics · Physics 2023-08-14 Valentin Daniel Paccoia , Orlando Panella , Pinaki Roy

We investigate two schemes for pumping spin adiabatically from a ferromagnet through an interacting quantum dot into a normal lead, which exploit the possibility to vary in time the ferromagnet's magnetization, either its amplitude or its…

Mesoscale and Nanoscale Physics · Physics 2013-05-17 Nina Winkler , Michele Governale , Jürgen König

Persistent and radiation-induced currents in distorted narrow quantum rings are theoretically investigated. We show that ring distorsions can be described using a geometrical potential term. We analyse the effect of this term on the current…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Yuriy V. Pershin , Carlo Piermarocchi

The persistent current of correlated electrons in a continuous one-dimensional ring with a single scatterer is calculated by solving the many-body Schrodinger equation for several tens of electrons interacting via the electron-electron…

Mesoscale and Nanoscale Physics · Physics 2008-03-31 Roman Krcmar , Andrej Gendiar , Martin Mosko , Radoslav Nemeth , Pavel Vagner , Lubos Mitas

A quantum-mechanical calculation of conductance in an open quantum dot is performed in the Landauer-B\"{u}ttiker formalism using a tight binding Hamiltonian with direct Coulomb interaction. The charge distribution in the dot is calculated…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 A. Aldea , A. Manolescu , V. Moldoveanu

We study the persistent current circulating along a mesoscopic ring with a dot side-coupled to it when threaded by a magnetic field. A cluster including the dot and its vicinity is diagonalized and embedded into the rest of the system. The…

Strongly Correlated Electrons · Physics 2009-11-07 E. V. Anda , C. Busser , G. Chiappe , M. A. Davidovich

The quantum oscillations in magnetic field of the critical current of asymmetric superconducting rings with different widths of the half-rings are shifted to opposite sides for measurement in the opposite direction. The value of this shift…

Superconductivity · Physics 2009-10-28 V. L. Gurtovoi , M. Exarchos , R. Shaikhaidarov , V. N. Antonov , A. V. Nikulov , V. A. Tulin

We investigate non-linear magneto-transport through a single level quantum dot coupled to ferromagnetic leads, where the electron spin is coupled to a large, external (pseudo)spin via an anisotropic exchange interaction. We find regimes…

Mesoscale and Nanoscale Physics · Physics 2012-04-12 Carlos López-Monís , Clive Emary , Gerold Kiesslich , Gloria Platero , Tobias Brandes

We report the solution of the persistent current in two coupled rings in the presence of external magnetic fluxes. We showed that the magnetic fluxes modify the global phase of the electronic wave function for multiple connected geometry…

Materials Science · Physics 2007-07-30 D. Schmeltzer , Hsuan-Yeh Chang

We show that a tight-binding model device consisting of a laterally connected ring at half filling in a tangent time-dependent magnetic field can in principle be designed to pump a purely spin current. The process exploits the spin-orbit…

Statistical Mechanics · Physics 2015-06-17 Michele Cini , Stefano Bellucci

We study a mesoscopic metallic ring threaded by a magnetic flux which varies linearly in time PhiM(t)=Phi t with a formalism based in Baym-Kadanoff-Keldysh non-equilibrium Green functions. We propose a method to calculate the Green…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 L. Arrachea

We study quantum evolution of the entanglement of a quantum dot connected to left and right leads initially maintained at chemical potentials $\mu_{L}$ and $\mu_{R}$ respectively, within the non-interacting resonant-level model. The full…

Strongly Correlated Electrons · Physics 2015-06-24 Auditya Sharma , Eran Rabani

We calculate current, spin current and tunnel magnetoresistance (TMR) for a quantum dot coupled to ferromagnetic leads in the presence of a square wave of bias voltage. Our results are obtained via time-dependent nonequilibrium Green…

Mesoscale and Nanoscale Physics · Physics 2015-05-13 F. M. Souza , J. A. Gomez

Advances in fabrication and control of quantum dots allow the realization of metastructures that may exhibit novel electrical transport phenomena. Here, we investigate the electrical current passing through one such metastructure, a system…

Mesoscale and Nanoscale Physics · Physics 2018-09-26 Chen-Yen Lai , Massimiliano Di Ventra , Michael Scheibner , Chih-Chun Chien

The set of moments and the distribution function of the one-electron current in a one-dimensional disordered ring with arbitrary magnetic flux are calculated.

Condensed Matter · Physics 2009-10-22 A. S. Cattaneo , A. Gamba , I. V. Kolokolov

We describe the effects of geometric torsion on the coherent motion of electrons along a thin twisted quantum ring. The geometric torsion inherent in the quantum ring triggers a quantum phase shift in the electrons' eigenstates, thereby…

Mesoscale and Nanoscale Physics · Physics 2015-05-13 Hisao Taira , Hiroyuki Shima

We study spin-polarized transient transport in a quantum dot coupled to two ferromagnetic leads subjected to a rectangular bias voltage pulse. Time-dependent spin-resolved currents, occupations, spin accumulation, and tunneling…

Mesoscale and Nanoscale Physics · Physics 2011-11-09 F. M. Souza , S. A. Leao , R. M. Gester , A. P. Jauho

Persistent currents and magnetization are considered for a two-dimensional electron (or gas of electrons) coupled to various magnetic fields. Thermodynamic formulae for the magnetization and the persistent current are established and the…

Condensed Matter · Physics 2009-10-31 Jean Desbois , Stephane Ouvry , Christophe Texier