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The Aharonov-Bohm effect is investigated in two-dimensional, single-terminal quantum rings in magnetic fields by using time-dependent density-functional theory. We find multiple transport loops leading to the oscillation periods of h/(en),…

Strongly Correlated Electrons · Physics 2010-06-22 V. Kotimaki , E. Rasanen

We study analytically a system made up of a quantum ring with a dipolar impurity and under the effect of an Aharonov-Bohm field. We calculate the exact values of the energies and we also get the exact expressions of the wave functions.

Quantum Physics · Physics 2021-02-16 Mourad Baazouzi , Mustafa Moumni , Mokhtar Falek

We study the role of impurity scattering on the photoluminescence (PL) emission of polarized magnetoexcitons. We consider systems where both the electron and hole are confined on a ring structure (quantum rings) as well as on a type-II…

Mesoscale and Nanoscale Physics · Physics 2009-01-23 Luis G. G. V. Dias da Silva , Sergio E. Ulloa , Alexander O. Govorov

The localization of electrons in the field of isolated nonmagnetic impurity atoms on the surface of a nanotube in a magnetic field is considered. A model of a Gaussian separable impurity potential capable of localizing an electron at any…

Mesoscale and Nanoscale Physics · Physics 2021-07-14 G. I. Rashba

We have investigated the Aharonov-Bohm effect in a one-dimensional GaAs/GaAlAs ring at low magnetic fields. The oscillatory magnetoconductance of these systems are for the first time systematically studied as a function of density. We…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 S. Pedersen , A. E. Hansen , A. Kristensen , C. B. Soerensen , P. E. Lindelof

We study the current magnification effect in presence of exchange scattering of electron from a magnetic impurity placed in one arm of an open mesoscopic ring. The exchange interaction causes entanglement of electron spin and impurity spin.…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 Colin Benjamin , Sandeep K. Joshi , Debendranath Sahoo , A. M. Jayannavar

We find a fine structure in the Aharonov-Bohm effect, characterized by the appearence of a new type of periodic oscillations having smaller fractional period and an amplitude, which may compare with the amplitude of the conventional…

Condensed Matter · Physics 2009-10-22 F. V. Kusmartsev , Minoru Takahashi

We study theoretically the optical properties of an exciton in a two-dimensional ring threaded by a magnetic flux. We model the quantum ring by a confining potential that can be continuously tuned from strictly one-dimensional to truly…

Mesoscale and Nanoscale Physics · Physics 2011-12-05 C. González-Santander , F. Domínguez-Adame , R. A. Römer

The problem of an impurity electron in a quantum ring (QR) in the presence of a radially directed strong external electric field is investigated in detail. Both an analytical and a numerical approach to the problem are developed. The…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 Boris S. Monozon , Mikhail V. Ivanov , Peter Schmelcher

The effect of electron-electron interaction on the electronic structure of Aharonov-Bohm (AB) graphene quantum rings (GQRs) is explored theoretically using the single-band tight-binding Hamiltonian and the mean-field Hubbard model. The…

Mesoscale and Nanoscale Physics · Physics 2015-06-22 R. Farghadan , A. Saffarzadeh , E. Heidari Semiromi

We theoretically consider the effects of having unintentional charged impurities in laterally coupled two-dimensional double (GaAs) quantum dot systems, where each dot contains one or two electrons and a single charged impurity in the…

Mesoscale and Nanoscale Physics · Physics 2015-05-27 Nga T. T. Nguyen , S. Das Sarma

The Kondo effect is investigated in a many-electron quantum ring as a function of magnetic field. For fields applied perpendicular to the plane of the ring a modulation of the Kondo effect with the Aharonov-Bohm period is observed. This…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 A. Fuhrer , T. Ihn , K. Ensslin , W. Wegscheider , M. Bichler

We study interaction and radial polarization effects on the the absorption spectrum of neutral bound magnetoexcitons confined in quantum-ring structures. We show that the size and orientation of the exciton's dipole moment, as well as the…

Mesoscale and Nanoscale Physics · Physics 2009-01-23 Luis G. Dias da Silva , Sergio E. Ulloa , Tigran V. Shahbazyan

The shape of an electronic droplet in the quantum Hall effect is sensitive to gradients of the magnetic field, even if they are placed outside the droplet. Magnetic impurities cause a fingering instability of the edge of the droplet,…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 P. Wiegmann

Within the framework of zero-range potential model in the ap-proach of effective mass, the impurity absorption by the complex Quantum Dot-Impurity Center in an external constant uniform magnetic field is considered. Under condition that the…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 V. D. Krevchik , A. B. Grunin , A. K. Aringazin , M. B. Semenov

Aharonov-Bohm oscillations are observed in a graphene quantum ring with a top gate covering one arm of the ring. As graphene is a gapless semiconductor this geometry allows to study not only the quantum interference of electrons with…

Mesoscale and Nanoscale Physics · Physics 2015-06-04 D. Smirnov , H. Schmidt , R. J. Haug

We report a comprehensive discussion of quantum interference effects due to the finite structure of excitons in quantum rings and their first experimental corroboration observed in the optical recombinations. Anomalous features that appear…

Magnetic impurities play an important role in many spintronics-related materials. Motivated by this fact, we study the anomalous Hall effect in the presence of magnetic impurities, focusing on two-dimensional electron systems with Rashba…

Materials Science · Physics 2009-11-13 Tamara S. Nunner , Gergely Zarand , Felix von Oppen

A narrow elliptic ring containing an electron threaded by a magnetic field B is studied. When the ring is highly flattened, the increase of B would lead to a big energy gap between the ground and excited states, and therefore lead to a…

Other Condensed Matter · Physics 2007-05-23 Shuping Situ , Yanzhang He , Chengguang Bao

We define a mesoscopic ring in a 2-dimensional electron gas (2DEG) interrupted by two tunnel barriers, enabling us to apply a well-defined potential difference between the two halves of the ring. The electron interference in the ring is…

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