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Related papers: Magnetic quantum dots and rings in two dimensions

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An orbital current mode peculiar to deformed quantum dots is theoretically investigated; first by using a simple model that allows to interpret analytically its main characteristics, and second, by numerically solving the microscopic…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 Llorens Serra , Antonio Puente , Enrico Lipparini

The Aharonov-Bohm effect is measured in a four-terminal open ring geometry based on a Ga[Al]As heterostructure. Two quantum dots are embedded in the structure, one in each of the two interfering paths. The number of electrons in the two…

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

The eigenvalue problem of the Hamiltonian of an electron confined to a plane and subjected to a perpendicular time-independent magnetic field which is the sum of a homogeneous field and an additional field contributed by a singular flux…

Quantum Physics · Physics 2009-10-31 H. -P. Thienel

The quantum dynamics of an atom with a magnetic quadrupole moment that interacts with an external field subject to a harmonic and a linear confining potentials is investigated. It is shown that the interaction between the magnetic…

Quantum Physics · Physics 2016-03-11 I. C. Fonseca , K. Bakke

We study the nonequilibrium spin transport through a quantum dot containing two spin levels coupled to the magnetic electrodes. A formula for the spin-dependent current is obtained and is applied to discuss the linear conductance and…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 Ping Zhang , Qi-Kun Xue , Yu-Peng Wang , X. C. Xie

We investigate the properties of a two-dimensional quantum ring under rotating and external magnetic field effects. We initially analyse the Landau levels and inertial effects on them. Among the results obtained, we emphasize that the…

Mesoscale and Nanoscale Physics · Physics 2023-06-21 Luís Fernando C. Pereira , Edilberto O. Silva

We apply quantum electrodynamical density functional theory to obtain the electronic density, the spin polarization, as well as the orbital and the spin magnetization of square periodic arrays of quantum dots or antidots subjected to the…

Mesoscale and Nanoscale Physics · Physics 2023-06-13 Vram Mughnetsyan , Vidar Gudmundsson , Nzar Rauf Abdullah , Chi-Shung Tang , Valeriu Moldoveanu , Andrei Manolescu

A Bloch point represents a three-dimensional hedgehog singularity of a magnetic vector field in which the magnetization vanishes. However, standard micromagnetic theory, developed for magnetic moments of fixed lengths, lacks full…

We have studied direct and Raman processes of the decay of electron spin states in a quantum dot via radiation of phonons corresponding to elastic twists. Universal dependence of the spin relaxation rate on the strength and direction of the…

Other Condensed Matter · Physics 2009-11-11 C. Calero , E. M. Chudnovsky , D. A. Garanin

We consider the magnetic field dependence of the chemical potential for parabolically confined quantum dots in a strong magnetic field. Approximate expressions based on the notion that the size of a dot is determined by a competition…

Condensed Matter · Physics 2009-10-22 S. -R. Eric Yang , A. H. MacDonald , M. D. Johnson

We present transport measurements of the Kondo effect in a double quantum dot charged with only one or two electrons, respectively. For the one electron case we observe a surprising quasi-periodic oscillation of the Kondo conductance as a…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 D. M. Schröer , A. K. Hüttel , K. Eberl , S. Ludwig , M. N. Kiselev , B. L. Altshuler

The properties of an exciton in a type II quantum dot are studied under the influence of a perpendicular applied magnetic field. The dot is modelled by a quantum disk with radius $R$, thickness $d$ and the electron is confined in the disk,…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 K. L. Janssens , B. Partoens , F. M. Peeters

Magnetotunneling spectroscopy was employed to probe the confinement in vertical Si/Ge double-barrier resonant tunneling diodes with regularly distributed Ge quantum dots. Their current-voltage characteristics reveal a step-like behavior in…

Mesoscale and Nanoscale Physics · Physics 2010-06-08 Oleksiy B. Agafonov , Christian Dais , Detlev Grützmacher , Rolf J. Haug

We investigate magnetic-field influenced time-dependent transport of Coulomb interacting electrons through a two-dimensional quantum ring in an electromagnetic cavity under non-equilibrium conditions described by a time-convolutionless…

Mesoscale and Nanoscale Physics · Physics 2013-07-02 Thorsten Arnold , Chi-Shung Tang , Andrei Manolescu , Vidar Gudmundsson

A system consisting of two neutral spin 1/2 particles is analyzed for two magnetic field perturbations: 1) an inhomogeneous magnetic field over all space, and 2) external fields over a half space containing only one of the particles. The…

Quantum Physics · Physics 2018-06-06 Yakir Aharonov , Jeeva Anandan , G. Jordan Maclay , Jun Suzuki

The confinement mechanism of electrons in gated circular quantum dots is studied in a sequence of models, from self-consistent 3D Hartree calculations to the semiclassical model of Shikin et al. Separation of the vertical from transverse…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 J. Martorell , D. W. L. Sprung

A small quantum ring with less than 10 electrons was studied by transport spectroscopy. For strong coupling to the leads a Kondo effect is observed and used to characterize the spin structure of the system in a wide range of magnetic…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 U. F. Keyser , C. Fuhner , S. Borck , R. J. Haug , M. Bichler , G. Abstreiter , W. Wegscheider

Spin-entanglement of two electrons occupying two spatial regions -- domains -- is expressed in a compact form in terms of spin-spin correlation functions. The power of the formalism is demonstrated on several examples ranging from…

Mesoscale and Nanoscale Physics · Physics 2009-04-10 A. Ramsak , J. Mravlje , T. Rejec

We consider a new quantum gate mechanism based on electron spins in coupled semiconductor quantum dots. Such gates provide a general source of spin entanglement and can be used for quantum computers. We determine the exchange coupling J in…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 Guido Burkard , Daniel Loss , David P. DiVincenzo

We consider an electron confined in a gated nanowire quantum dot (NQD) with arbitrarily strong spin-orbit coupling (SOC) and weak static magnetic field, and treat the latter as a perturbation to seek the maximal spin-motion entangled states…

Mesoscale and Nanoscale Physics · Physics 2024-04-23 Kuo Hai , Xuefang Deng , Qiong Chen , Wenhua Hai
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