Related papers: Vertically coupled double quantum dots in magnetic…
Three terminal tunnelling experiments on quantum dots in the Coulomb blockade regime allow a quantitative determination of the coupling strength of individual quantum states to the leads. Exploiting this insight we have observed independent…
Exact eigenstates of the parallel coupled double quantum dots attached to the non-interacting leads taken in zero-bandwidth limit are analytically obtained in each particle and spin sector. The ground state of the half-filled system is…
The two-dimensional Wigner crystals are studied with the variational quantum Monte Carlo method. The close relationship between the ground-state wavefunction and the collective excitations in the system is illustrated, and used to guide the…
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 double-quantum-dot coupled to electrodes with spin-dependent splitting of chemical potentials (spin bias) is investigated theoretically by means of the Green's functions formalism. By applying a large spin bias, the quantum spin in a…
The Kondo effect is a key many-body phenomenon in condensed matter physics. It concerns the interaction between a localised spin and free electrons. Discovered in metals containing small amounts of magnetic impurities, it is now a…
We consider a lateral double-dot system in the Coulomb blockade regime with a single spin-1/2 on each dot, mutually coupled by an anti-ferromagnetic exchange interaction. Each of the two dots is contacted by two leads. We demonstrate that…
We studied the exciton energy in a type II quantum disk as a function of the magnetic field, disk radius R and height d. We found angular momentum transitions for dots with d >> 2R. Application of an electric field perpendicular to the disk…
We investigate experimentally and theoretically the behavior of Coulomb blockade (CB) peaks in a magnetic field that couples principally to the ground-state spin (rather than the orbital moment) of a chaotic quantum dot. In the first part,…
The transport through a quantum wire exposed to two magnetic spikes in series is modeled. We demonstrate that quantum dots can be formed this way which couple to the leads via magnetic barriers. Conceptually, all quantum dot states are…
In the limit of low particle density, electrons confined to a quantum dot form strongly correlated states termed Wigner molecules, in which the Coulomb interaction causes the electrons to become highly localized in space. By using an…
We predict a huge interference effect contributing to the conductance through large ultra-clean quantum dots of chaotic shape. When a double-dot structure is made such that the dots are the mirror-image of each other, constructive…
We present a theory of electronic properties and the spin blockade phenomena in a gated linear triple quantum dot. Quadruple points where four different charge configurations are on resonance, particularly involving (1,1,1) configuration,…
We analyze coherent spin phenomena in triple quantum dots in triangular configuration under crossed DC and AC magnetic fields. In particular, we discuss the interplay between Aharonov-Bohm current oscillations, coherent electron trapping…
Using exact diagonalization we study the low energy Hilbert space of the two-electron, two-quantum dot artificial molecule under a perpendicular magnetic field. We show that electrons bind to vortices to induce several spin transitions…
For a double quantum dot system in a parallel geometry, we demonstrate that by combining the effects of a flux and driving an electrical current through the structure, the spin correlations between electrons localized in the dots can be…
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…
We propose an idea for probing spin states of two coupled quantum dots (CQD), by the dc Josephson current flowing through them. This theory requires weak coupling between CQD and electrodes, but allows arbitrary inter-dot tunnel coupling,…
The effects of spin-orbit (SO) coupling arising from the confinement potential in single and two vertically-coupled quantum dots have been investigated. Our work indicates that a dot containing a single electron shows the lifting of the…
Crossings between spin-singlet and spin-triplet lowest states are analyzed within the model of a two-electron quantum dot in a perpendicular magnetic field. The explicit expressions in terms of the magnetic field, the magnetic quantum…