相关论文: Isospin phases of vertically coupled double quantu…
We have studied the structure and dipole charge density response of nanorings as a function of the magnetic field using local-spin density functional theory. Two small rings consisting of 12 and 22 electrons confined by a positively charged…
In the framework of the Relativistic Mean Field Approach a pseudospin dependence of the residual forces in nuclei is considered. It is shown that this dependence is relatively weak. As a consequence, a pseudospin dependence of the…
We study the low energy states of finite spin chains with isotropic (Heisenberg) and anisotropic (XY and Ising-like) exchange interaction with uniform and non-uniform coupling constants. We show that for an odd number of sites a spin…
Coupled semiconductor quantum dots form artificial molecules where relevant energy scales controlling the interacting ground state can be easily tuned. By applying an external magnetic field it is possible to drive the system from a weak to…
Theoretical study of the indirect coupling of nuclear spins (qubits) embedded into a mesoscopic ring and in a finite length quantum wire in a magnetic field is presented. It is found that the hyperfine interaction, via the conduction…
Quantum-state engineering, i.e., active manipulation over the coherent dynamics of suitable quantum-mechanical systems, has become a fascinating prospect of modern physics. Here we discuss the dynamics of two interacting electrons in a…
Coulomb and spin blockade spectroscopy investigations have been performed on an electrostatically defined ``artificial molecule'' connected to spin polarized leads. The molecule is first effectively reduced to a two-level system by placing…
Theoretical approaches to one-dimensional and quasi-one-dimensional quantum rings with a few electrons are reviewed. Discrete Hubbard-type models and continuum models are shown to give similar results governed by the special features of the…
Frustrated spin models may lead to the formation of both classical non-collinear spin structures and unique quantum phases including highly entangled quantum spin liquids. Here, we study the entanglement and spatial quantum correlations in…
We study a two-electron quantum dot molecule in a magnetic field by the direct diagonalization of the Hamiltonian matrix. The ground states of the molecule with the total spin S=0 and S=1 provide a possible realization for a qubit of a…
The spin-configuration of semiconductor artificial molecules consisting of quantum dots and spin field effect transistors is studied theoretically. We find that the antiferromagnetic spin configuration can be changed to the ferromagnetic…
We theoretically explore the possibility of creating spin quantum entanglement in a system of two electrons confined respectively in two vertically coupled quantum dots in the presence of Rashba type spin-orbit coupling. We find that the…
We study detailed classical-quantum correspondence for a cluster system of three spins with single-axis anisotropic exchange coupling. With autoregressive spectral estimation, we find oscillating terms in the quantum density of states…
Energy spectra and spin configurations of a system of N=4 electrons in lateral double quantum dots (quantum dot Helium molecules) are investigated using exact diagonalization (EXD), as a function of interdot separation, applied magnetic…
The electron-electron correlations in a many-electron (Ne = 1, 2,..., 5) quantum dot confined by a parabolic potential is investigated in the presence of a single magnetic ion and a perpendicular magnetic field. We obtained the energy…
We show that the low lying spin states of two electrons in a semiconductor quantum dot can be strongly mixed by electron-electron asymmetric exchange. This mixing is generated by the coupling of electron spin to its orbital motion and to…
In this work, we investigate the electronic and optical properties of the b-AsP quantum dots(QDs) and quantum rings(QRs) with different edge types in the presence of an in-plane electric field and a perpendicular magnetic field utilizing…
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…
We briefly report on calculated addition spectra for electrons in a circular quantum dot with perpendicular magnetic field. We compare our current density functional theory calculations with recent experiments by Tarucha et al. [PRL 77,…
We study the spin filling of a semiconductor quantum dot using excited-state spectroscopy in a strong magnetic field. The field is oriented in the plane of the two-dimensional electron gas in which the dot is electrostatically defined. By…