Related papers: Kondo and mixed valence regimes in multi-level qua…
Strong electron and spin correlations in a double-quantum-dot (DQD) can give rise to different quantum states. We observe a continuous transition from a Kondo state exhibiting a single-peak Kondo resonance to another exhibiting a double…
The interplay between the Kondo effect and the inter-dot magnetic interaction in a coupled-dot system is studied. An exact result for the transport properties at zero temperature is obtained by diagonalizing a cluster, composed by the…
The interplay between the coupling of an interacting quantum dot to a conduction band and its connection to localized levels has been studied in a triple quantum dot arrangement. The electronic Dicke effect, resulting from quasi-resonant…
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…
Many heavy fermion materials are known to crossover from the Kondo lattice regime to the mixed-valent regime or vice-versa as a function of pressure or doping. We study this crossover theoretically by employing the periodic Anderson model…
The out-of-equilibrium transport properties of a double quantum dot system in the Kondo regime are studied theoretically by means of a two-impurity Anderson hamiltonian with interimpurity hopping. The hamiltonian is solved by means of a…
We propose a nanoscale device consisting of a double quantum dot with strong intra- and inter- dot Coulomb repulsions. In this design, the current can only flow through the lower dot, but is triggered by the gate-controlled occupancy of the…
Transport through a quantum dot (QD) in the Kondo regime shows alternating regions of high and low conductance when both an external magnetic field and the gate potential controlling the depth of the QD potential are varied. We present a…
While the properties of the Kondo model in equilibrium are very well understood, much less is known for Kondo systems out of equilibrium. We study the properties of a quantum dot in the Kondo regime, when a large bias voltage V and/or a…
We study a small spin-degenerate quantum dot with even number of electrons, weakly connected by point contacts to the metallic electrodes, and subject to an external magnetic field. If the Zeeman energy B is equal to the single-particle…
The non-Fermi-liquid properties of an ultrasmall quantum dot coupled to a lead and to a quantum box are investigated. Tuning the ratio of the tunneling amplitudes to the lead and box, we find a line of two-channel Kondo fixed points for…
We investigate the Fano-Kondo interplay in an Aharonov-Bohm ring with an embedded non-interacting quantum dot and a Coulomb interacting quantum dot. Using a slave-boson mean-field approximation we diagonalize the Hamiltonian via scattering…
A quantum dot with spin-orbit interaction can work as an efficient spin filter if it is connected to N (> 2) external leads via tunnel barriers. When an unpolarized current is injected to a quantum dot from a lead, polarized currents are…
We study a strongly interacting "quantum dot 1" and a weakly interacting "dot 2" connected in parallel to metallic leads. Gate voltages can drive the system between Kondo-quenched and non-Kondo free-moment phases separated by…
We investigate entanglement between electrons in serially coupled double quantum dots attached to non interacting leads. In addition to local repulsion we consider the influence of capacitive inter-dot interaction. We show how the…
Off-resonance conductance through weakly coupled quantum dots ("valley conductance") is governed by cotunneling processes in which a large number of dot states participate. Virtually the same states participate in the transport at…
We study peculiarities of transport through a Coulomb blockade system tuned to the vicinity of the spin transition in its ground state. Such transitions can be induced in practice by application of a magnetic field. Tunneling of electrons…
We study the Kondo effect in a quantum dot which is coupled to ferromagnetic leads and analyse its properties as a function of the spin polarization of the leads. Based on a scaling approach we predict that for parallel alignment of the…
We study the electronic transport in a double quantum dot structure connected to leads in the Kondo regime for both series and parallel arrangements. By applying a finite-U slave boson technique in the mean field approximation we explore…
We investigate Kondo effect and spin blockade observed on a many-electron quantum dot and study the magnetic field dependence. At lower fields a pronounced Kondo effect is found which is replaced by spin blockade at higher fields. In an…