Related papers: From spin and orbital SU(4) to spin SU(2) Kondo ef…
Quantum entanglement between an impurity spin and electrons nearby is a key property of the single-channel Kondo effects. We show that the entanglement can be detected by measuring electron conductance through a double quantum dot in an…
Spintronics devices rely on spin-dependent transport behavior evoked by the presence of spin-polarized electrons. Transport through nanostructures, on the other hand, is dominated by strong Coulomb interaction. We study a model system in…
It is shown that the low-energy spin states of double quantum dots (DQD) with even electron occupation number $N$ possess the symmetry SO(4) similar to that of a rigid rotator familiar in quantum mechanics (rotational spectra of H$_2$…
We study the conductance through a triangular triple quantum dot, which are connected to two noninteracting leads, using the numerical renormalization group (NRG). It is found that the system shows a variety of Kondo effects depending on…
Equilibrium transport properties of a single-level quantum dot tunnel-coupled to ferromagnetic leads and exchange-coupled to a side nonmagnetic reservoir are analyzed theoretically in the Kondo regime. The equilibrium spectral functions and…
Electron tunneling through a system formed by two coupled quantum dots in a parallel geometry is considered within a generalized Anderson model. The dots are assumed to have nearly equal radii but different (and tunable) gate voltages. In…
We investigate theoretically and experimentally the singlet-triplet Kondo effect induced by a magnetic field in a molecular junction. Temperature dependent conductance, $G(T)$, is calculated by the numerical renormalization group, showing a…
We study finite-temperature properties of the Kondo effect in a carbon nanotube (CNT) quantum dot using the Wilson numerical renormalization group (NRG). In the absence of magnetic fields, four degenerate energy levels of the CNT consisting…
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 study the interplay between Coulomb blockade and the Kondo effect in quantum dots. We use a self-consistent scheme which describes mesoscopic devices in terms of a collective phase variable (slave rotor) and quasiparticle degrees of…
Kondo conduction has been observed in a quantum dot with an even number of electrons at the Triplet-Singlet degeneracy point produced by applying a small magnetic field $B$ orthogonal to the dot plane. At a much larger field $ B \sim B_*$,…
We study the Kondo effect in the electron transport through a quantum dot coupled to ferromagnetic leads, using a real-time diagrammatic technique which provides a systematic description of the nonequilibrium dynamics of a system with…
We calculate the spectral density and occupations of a system of two capacitively coupled quantum dots, each one connected to its own pair of conducting leads, in a regime of parameters in which the total coupling to the leads for each dot…
We investigate thermoelectric properties of correlated quantum dots and molecules, described by a single level Anderson model coupled to conduction electron leads, by using Wilson's numerical renormalization group method. In the Kondo…
Electron tunneling through a double quantum dot molecule side attached to a quantum wire, in the Kondo regime, is studied. The mean-field finite-U slave-boson formalism is used to obtain the solution of the problem. We found conductance…
We report on cotunneling spectroscopy magnetoconductance measurements of multi-hole ultraclean carbon nanotube quantum dots in the SU(4) Kondo regime with strong spin-orbit coupling. Successive shells show a gradual weakening of the Kondo…
We demonstrate a tunable Kondo effect realized in small quantum dots. We can switch our dot from a Kondo impurity to a non-Kondo system as the number of electrons on the dot is changed from odd to even. We show that the Kondo temperature…
We study the non-equilibrium regime of the Kondo effect in a quantum dot laterally coupled to a narrow wire. We observe a split Kondo resonance when a finite bias voltage is imposed across the wire. The splitting is attributed to the…
Based on ab-initio calculations we identify possible scenarios for the Kondo effect due to Co ad-atoms on graphene. General symmetry arguments show that for magnetic atoms in high-symmetry positions, the Kondo effect in graphene is…
Non-equilibrium Green's function technique has been used to calculate spin-dependent electronic transport through a quantum dot in the Kondo regime. The dot is described by the Anderson Hamiltonian and is coupled either symmetrically or…