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We investigate the effects of the shape of quantum dots on their far-infrared absorption in an external magnetic field by a model calculation. We focus our attention on dots with a parabolic confinement potential deviating from the common…

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

Many-particle electron states in semiconductor quantum dots with carrier-mediated ferromagnetism are studied theoretically within the self-consistent Boltzmann equation formalism. Depending on the conditions, a quantum dot may contain there…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Alexander O. Govorov

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

We derive a self-consistent local variant of the Thomas-Fermi approximation for (quasi-)two-dimensional (2D) systems by localizing the Hartree term. The scheme results in an explicit orbital-free representation of the electron density and…

Strongly Correlated Electrons · Physics 2013-02-04 E. Rasanen , S. Pittalis , G. Bekcioglu , I. Makkonen

We consider circular and elliptic quantum dots with parabolic external confinement, containing 0 - 22 electrons and with values of r_s in the range 0 < r_s < 3. We perform restricted and unrestricted Hartree-Fock calculations, and further…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 Clare Sloggett , Oleg Sushkov

Magnetic properties of two and three-dimensional clusters of quantum dots are studied with exact diagonalization of a generalized Hubbard model. We study the weak coupling limit, where the electrons interact only within a quantum dot and…

Strongly Correlated Electrons · Physics 2009-11-13 J. -P. Nikkarila , M. Koskinen , M. Manninen

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

Low-lying energy levels of two interacting electrons confined in a two-dimensional parabolic quantum dot in the presence of an external magnetic field have been revised within the frame of a novel model. The present formalism, which gives…

Quantum Physics · Physics 2009-10-11 Bulent Gonul , Ebru Bakir , Koray Koksal

We have performed Hartree-Fock calculations of electronic structure of N \le 10 electrons in a quantum dot modeled with a confining Gaussian potential well. We discuss the conditions for the stability of N bound electrons in the system. We…

Mesoscale and Nanoscale Physics · Physics 2013-05-28 Sergio S. Gomez , Rodolfo H. Romero

Spherical shaped Si quantum dots (QDs) embedded into the SiO2 substrate are considered in the single sub-band effective mass approach. Nonparabolicity of the Si conduction band is described by the energy dependence of electron effective…

Mesoscale and Nanoscale Physics · Physics 2015-05-14 I. Filikhin , S. G. Matinyan , B. K. Schmid , B. Vlahovic

A model for quantum dots is proposed, in which the motion of a few electrons in a three-dimensional harmonic oscillator potential under the influence of a homogeneous magnetic field of arbitrary direction is studied. The spectrum and the…

Mesoscale and Nanoscale Physics · Physics 2009-10-30 W. D. Heiss , R. G. Nazmitdinov

Recent measurements of electron escape from a non-equilibrium charged quantum dot are interpreted within a 2D separable model. The confining potential is derived from 3D self-consistent Poisson-Thomas-Fermi calculations. It is found that…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 J. Martorell , D. W. L. Sprung , P. A. Machado , C. G. Smith

We consider the motion of electrons confined to a two dimensional plane with an externally applied perpendicular inhomogeneous magnetic field, both with and without a Coulomb potential. We find that as long as the magnetic field is…

Mesoscale and Nanoscale Physics · Physics 2016-08-05 C. A. Downing , M. E. Portnoi

In order to understand the orbital and spin magnetization of a confined electronic system we analyze these ground state properties in the transition from a quantum dot to a quantum ring of finite thickness. The Coulomb interaction between…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Gabriel Vasile , Vidar Gudmundsson , Andrei Manolescu

Quantum dots with conduction electrons or holes originating from several bands are considered. We assume the particles are confined in a harmonic potential and assume the electrons (or holes) belonging to different bands to be different…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 K. Karkkainen M. Koskinen , S. M. Reimann , M. Manninen

This article reports on tunable electron backscattering investigated with the biased tip of a scanning force microscope. Using a channel defined by a pair of Schottky gates, the branched electron flow of ballistic electrons injected from a…

Mesoscale and Nanoscale Physics · Physics 2016-02-11 R. Steinacher , A. A. Kozikov , C. Rössler , C. Reichl , W. Wegscheider , K. Ensslin , T. Ihn

Silicon quantum computing has the potential to revolutionize technology with capabilities to solve real-life problems that are computationally complex or even intractable for modern computers [1] by offering sufficient high quality qubits…

Mesoscale and Nanoscale Physics · Physics 2024-09-24 Dylan H. Liang , MengKe Feng , Philip Y. Mai , Jesus D. Cifuentes , Andrew S. Dzurak , Andre Saraiva

We study a system in which electrons in a two-dimensional electron gas are confined by a nonhomogeneous nuclear spin polarization. The system consists of a heterostructure that has non-zero nuclei spins. We show that in this system…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Yu. V. Pershin

Kohn-Sham spin-density functional theory provides an efficient and accurate model to study electron-electron interaction effects in quantum dots, but its application to large systems is a challenge. An efficient algorithm for the…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Hong Jiang , Harold U. Baranger , Weitao Yang

A tool for the identification of the shape of quantum dots is developed. By preparing a two-electron quantum dot, the response of the low-lying excited states to a homogeneous magnetic field, i.e. their spin and parity oscillations, is…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 P. S. Drouvelis , P. Schmelcher , F. K. Diakonos