Related papers: Single- and few-electron dynamic quantum dots in a…
We have studied the magnetic field dependence of the ground state energies in a small Si quantum dot. At low fields the first five electrons are added in a spin-up -- spin-down sequence minimizing the total spin. This sequence does not hold…
We report on strong renormalization encountered in periodically driven interacting quantum dots in the non-adiabatic regime. Correlations between lead and dot electrons enhance or suppress the amplitude of driving depending on the sign of…
We found that a downwardly concave entanglement evolution of the ground state of a two-electron axially symmetric quantum dot testifies that a shape transition from a lateral to a vertical localization of two electrons under a perpendicular…
We develop a theoretical model for the description of electron dynamics in coupled quantum wires when the local magnetic moment is formed in one of the wires. We employ a single-particle Hamiltonian that takes account of the specific…
We present a theoretical study of the electronic transport through a many-level quantum dot driven by time-dependent signals applied at the contacts to the leads. If the barriers oscillate out of phase the system operates like a turnstile…
Periodic driving of quantum dots is analyzed as a basis for developing dynamic switching devices. We study transport through periodically modulated energy levels which are coupled to leads via tunneling coefficients. Utilizing Floquet…
Electronic states and transport phenomena in semiconductor quantum dots are studied theoretically. Taking account of the electron-electron Coulomb interaction by the exact diagonalization method, the ground state and low-lying excited…
Using an exact diagonalization technique within a generalized Mott-Hubbard Hamiltonian, we predict the existence of a ground state persistent current in coherent two-dimensional semiconductor quantum dot arrays pierced by an external…
In recent years, there has been an increasing interest in nanoelectromechanical devices, current-driven quantum machines, and the mechanical effects of electric currents on nanoscale conductors. Here, we carry out a thorough study of the…
We report the realization of a quadruple quantum dot device in a square-like configuration where a single electron can be transferred on a closed path free of other electrons. By studying the stability diagrams of this system, we…
Using standard microfabrication techniques it is now possible to construct devices, which appear to reliably manipulate electrons one at a time. These devices have potential use as building blocks in quantum computing devices, or as a…
We investigate current fluctuations in a three-terminal quantum dot in the sequential tunneling regime. Dynamical spin blockade can be induced when the spin-degeneracy of the dot states is lifted by a magnetic field. This results in…
We investigate the effect of a quantised vibrational mode on electron tunneling through a chain of three quantum dots. The outer dots are coupled to voltage leads, but the position of the central dot is not rigidly fixed. Motion of the…
We study the dynamics of a quantum dot embedded in a three-dimensional microcavity in the strong coupling regime in which the quantum dot exciton has an energy close to the frequency of a confined cavity mode. Under the continuous pumping…
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…
We study some aspects of the quantum theory of a charged particle moving in a time-independent, uni-directional magnetic field. When the field is uniform, we make a few clarifying remarks on the use of angular momentum eigenstates and…
A quantum pumping mechanism which produces dc current or voltage in response to a cyclic deformation of the confining potential in an open quantum dot is reported. The voltage produced at zero current bias is sinusoidal in the phase…
We develop a theory for spin transport and magnetization dynamics in a quantum-dot spin valve, i.e., two magnetic reservoirs coupled to a quantum dot. Our theory is able to take into account effects of strong correlations. We demonstrate…
A study of magneto-transport through quantum dots is presented. The model allows to analyze tunnelling both from bulk-like contacts and from 2D accumulation layers. The fine features in the I-V characteristics due to the quantum dot states…
The electron motion in rather strong magnetic fields (when only the lowest Landau level is populated) is considered. In this case the electron kinetic energy is frozen out and the electrons are guided by slowly varied potential. Using the…