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We study repeated (noncontinuous) measurements on the electron spin in a quantum dot and find that the measurement technique may lead to a different met$ or mechanism to realize nuclear spin polarization. While it may be used in any case,…

Quantum Physics · Physics 2011-07-28 Lian-Ao Wu

We solve the problem of a few electrons in a two-dimensional harmonic confinement using quantum mechanical exact diagonalization technique, on one hand, and classical mechanics, on the other hand. The quantitative agreement between the…

Mesoscale and Nanoscale Physics · Physics 2015-06-25 J. -P. Nikkarila , M. Manninen

Laterally coupled quantum dot molecules are studied using exact diagonalization techniques. We examine the two-electron singlet-triplet energy difference as a function of magnetic field strength and investigate the magnetization and vortex…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 M. Helle , A. Harju , R. M. Nieminen

We investigate coherent electron transport through a parallel circuit of two quantum dots, each of which has a single tunable energy level. Electrons tunneling via each dot from the left lead interfere with each other at the right lead. It…

Mesoscale and Nanoscale Physics · Physics 2016-08-31 Sam Young Cho , Ross H. McKenzie , Kicheon Kang , Chul Koo Kim

In magnetically-doped quantum dots changing the carrier occupancy, from open to closed shells, leads to qualitatively different forms of carrier-mediated magnetic ordering. While it is common to study such nanoscale magnets within a mean…

Mesoscale and Nanoscale Physics · Physics 2015-10-28 J. M. Pientka , R. Oszwałdowski , A. G. Petukhov , J. E. Han , Igor Žutić

Electron spins in semiconductor quantum dots are good candidates of quantum bits for quantum information processing. Basic operations of the qubit have been realized in recent years: initialization, manipulation of single spins, two qubit…

An analytic expansion of the exact one-electron momentum density of the Hooke's atom is derived for the case k = 1/4. Electron correlation is shown to have opposite effects on the momentum density, compared with the Moshinsky's atom, but is…

Chemical Physics · Physics 2007-05-23 S. Ragot

We investigate a lateral semiconductor quantum dot with a large number of electrons in the limit of strong coupling to the leads. A Kondo effect is observed and can be tuned in a perpendicular magnetic field. This Kondo effect does not…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 C. Fuhner , U. F. Keyser , R. J. Haug , D. Reuter , A. D. Wieck

We consider a problem of electron motion in different media and magnetic field. It is shown that in case of nonmoving medium and constant homogenious magnetic field the electron energies are quantized. We also discuss the general problem of…

High Energy Physics - Phenomenology · Physics 2011-05-23 I. Balantsev , Yu. Popov , A. Studenikin

The time-dependent Schrodinger equation of a many particle spin system consisting of an electron in a quantum dot interacting with the spins of the nuclei (N) in the dot due to hyperfine interaction is solved exactly for a given arbitrary…

Quantum Physics · Physics 2007-05-23 A. K. Rajagopal

We consider a Kondo spin that is coupled antiferromagnetically to a large chaotic quantum dot. Such a dot is described by the so-called universal Hamiltonian and its electrons are interacting via a ferromagnetic exchange interaction. We…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 Stefan Rotter , Y. Alhassid

We study the ground state properties of rectangular quantum dots by using the spin-density-functional theory and quantum Monte Carlo methods. The dot geometry is determined by an infinite hard-wall potential to enable comparison to…

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

Using a classical and quantum mechanical analysis, we show that the magnetic field gives rise to dynamical symmetries of a three-dimensional axially symmetric two-electron quantum dot with a parabolic confinement. These symmetries manifest…

Condensed Matter · Physics 2009-11-07 N. S. Simonovic , R. G. Nazmitdinov

We analyze the equilibrium and non-equilibrium frequency-dependent spin current noise and spin conductance through a quantum dot in the local moment regime. Spin current correlations are shown to behave markedly differently from charge…

Mesoscale and Nanoscale Physics · Physics 2015-05-13 C. P. Moca , I. Weymann , G. Zarand

We study the effect of a magnetic field on the conductance through a strongly interacting quantum dot by using the finite temperature extension of Wilson's numerical renormalization group method to dynamical quantities. The quantum dot has…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 T. A. Costi

The zero bias conductance of quantum dots coupled to ferromagnetic leads is investigated. In the strong coupling regime, it is found that the conductance is a non-monotonic function of the angle between the magnetisation directions in the…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 J. Fransson

Electron states in a inhomogeneous Ge/Si quantum dot array with groups of closely spaced quantum dots were studied by conventional continuous wave ($cw$) ESR and spin-echo methods. We find that the existence of quantum dot groups allows to…

Mesoscale and Nanoscale Physics · Physics 2014-12-23 A. F. Zinovieva , N. P. Stepina , A. I. Nikiforov , A. V. Nenashev , A. V. Dvurechenskii , L. V. Kulik , N. A. Sobolev , M. C. Carmo

This chapter takes a microscopic view of quantum tunneling of magnetization (QTM) in single-molecule magnets (SMMs), focusing on the interplay between exchange and anisotropy. Careful consideration is given to the relationship between…

Mesoscale and Nanoscale Physics · Physics 2013-03-04 Junjie Liu , Enrique del Barco , Stephen Hill

We consider free electrons in rectangular quantum dots, with either hard wall boundary conditions or anharmonic confinement. In both cases, due to finite size effects, a homogeneous electric field applied along one of the rectangular axis…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Stephane Pleutin

The possibility of coherent radiation by molecular magnets is investigated. It is shown that to realize the coherent radiation, it is necessary to couple the considered sample to a resonant electric circuit. A theory for describing this…

Mesoscale and Nanoscale Physics · Physics 2015-06-25 V. I. Yukalov , E. P. Yukalova