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We present results from a theoretical and experimental study of spin-splitting in small open lateral quantum dots (i.e. in the regime when the dot is connected to the reservoirs via leads that support one or more propagating modes). We…

Mesoscale and Nanoscale Physics · Physics 2008-04-04 M. Evaldsson , I. V. Zozoulenko , M. Ciorga , P. Zawadzki , A. S. Sachrajda

The magnetization of quantum dots is discussed in terms of a relatively simple but exactly solvable model Hamiltonian. The model predicts oscillations in spin polarization as a function of dot radius for a fixed electron density. These…

Mesoscale and Nanoscale Physics · Physics 2007-10-11 A. Bansil , D. Nissenbaum , B. Barbiellini , R. Saniz

Semiconductor quantum dots (QDs) doped with magnetic impurities have been a focus of continuous research for a couple of decades. A significant effort has been devoted to studies of magnetic polarons (MP) in these nanostructures. These…

Materials Science · Physics 2023-07-19 D. Rederth , R. Oszwaldowski , A. G. Petukhov , J. Pientka

We use the high sensitivity to magnetic flux of mesoscopic conductance fluctuations in large quantum dots to investigate changes in the two-dimensional electron dispersion caused by an in-plane magnetic field. In particular, changes in…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 D. M. Zumbuhl , J. B. Miller , C. M. Marcus , V. I. Fal'ko , T. Jungwirth , J. S. Harris

We use density-functional methods to study the effects of an external magnetic field on two-dimensional quantum dots with a rectangular hard-wall confining potential. The increasing magnetic field leads to spin polarization and formation of…

Strongly Correlated Electrons · Physics 2009-11-10 E. Räsänen , A. Harju , M. J. Puska , R. M. Nieminen

The emission spectra of individual self-assembled quantum dots containing a single magnetic Mn atom differ strongly from dot to dot. The differences are explained by the influence of the system geometry, specifically the in-plane asymmetry…

Other Condensed Matter · Physics 2009-11-11 Y. Leger , L. Besombes , L. Maingault , D. Ferrand , H. Mariette

We report results of a Monte Carlo study of doped, diluted magnetic semiconductors in the low carrier density (insulating) regime. We find that the system undergoes a transition from a paramagnet at high temperatures to a ferromagnet at low…

Materials Science · Physics 2007-05-23 Xin Wan , R. N. Bhatt

We employ the density functional Kohn-Sham method in the local spin-density approximation to study the electronic structure and magnetism of quasi one-dimensional periodic arrays of few-electron quantum dots. At small values of the lattice…

Mesoscale and Nanoscale Physics · Physics 2015-06-25 K. Karkkainen , M. Koskinen , S. M. Reimann , M. Manninen

Magnetoresistance in two-dimensional array of Ge/Si quantum dots was studied in a wide range of zero-magnetic field conductances, where the transport regime changes from hopping to diffusive one. The behavior of magnetoresistance is found…

Mesoscale and Nanoscale Physics · Physics 2015-06-17 N. P. Stepina , E. S. Koptev , A. G. Pogosov , A. V. Dvurechenskii , A. I. Nikiforov , E. Yu. Zhdanov , Y. M. Galperin

Both spin and orbital degrees of freedom contribute to the magnetic moment of isolated atoms. However, when inserted in crystals, atomic orbital moments are quenched because of the lack of rotational symmetry that protects them when…

Mesoscale and Nanoscale Physics · Physics 2015-09-10 P. Potasz , J. Fernandez-Rossier

We present a theory for the electronic and magneto-optical properties of spherical quantum dots consisting of an inner core surrounded by an outer shell. This core-shell quantum dot is doped by magnetic Mn impurities all of which are…

Mesoscale and Nanoscale Physics · Physics 2015-08-28 G. D. Sanders , C. J. Stanton

We calculate the magnetization of quantum dots deviating from circular symmetry for noninteracting electrons or electrons interacting according to the Hartree approximation. For few electrons the magnetization is found to depend on their…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Ingibjorg Magnusdottir , Vidar Gudmundsson

We show that a double quantum-dot system made of diluted magnetic semiconductor behaves unlike usual molecules. In a semiconductor double quantum dot or in a diatomic molecule, the ground state of a single carrier is described by a…

Other Condensed Matter · Physics 2009-11-11 Wei Zhang , Tianming Dong , Alexander O. Govorov

We consider electronic transport through laterally parallel double open quantum dots embedded in a quantum wire in a perpendicular magnetic field. The coupling modes of the dots are tunable by adjusting the strength of a central barrier and…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Chi-Shung Tang , Wing Wa Yu , Vidar Gudmundsson

Recently, diluted Magnetic Semiconductors (DMS) doped with a small concentration of magnetic impurities, especially DMS doped with transition metal, inducing ferromagnetic DMSs have attracted a great interest. Using the Monte Carlo method…

Materials Science · Physics 2011-06-06 Lalla Btissam Drissi

The mechanical effects in finite two-dimensional electron systems (quantum dots or droplets) in a strong perpendicular magnetic field are studied. It is shown that, due to asymmetry of the cyclotron dynamics, an additional in-plane electric…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Lucjan Jacak , Jurij Krasnyj , Dorota Jacak , Arkadiusz Wojs

We study the transport behavior induced by a small bias voltage through a quantum dot connected to one-channel finite-size wires. We describe the quantum dot by the Hubbard-Kondo which is solved by means of a quantum Monte Carlo method. We…

Mesoscale and Nanoscale Physics · Physics 2015-02-13 Alberto Camjayi , Liliana Arrachea

By muon spin rotation we investigated the magnetic properties of a series of highly Na doped NaxCoO2 single crystals with 0.78(1)<x<0.97(1). Our data provide evidence for an intrinsically inhomogeneous magnetic state which can be described…

Magnetization of soft-ferromagnetic nano- and microtubes of nanometer-thin walls (a single-widening rolled-up nanomembranes) is theoretically studied using analytical and numerical approaches including different stress-induced anisotropies.…

Mesoscale and Nanoscale Physics · Physics 2016-09-12 Andrzej Janutka

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