Related papers: Orbital and spin Kondo effects in a double quantum…
We study the charge current transmitted through the correlated quantum dot characterized by a finite magnitude of the Coulomb interaction |U|. At low temperatures the correlations can lead to appearance of the spin (for U>0) or charge (for…
We calculate the nonequilibrium conductance of a system of two capacitively coupled quantum dots, each one connected to its own pair of conducting leads. The system has been used recently to perform pseudospin spectroscopy by controlling…
We investigate the Kondo effect in a quantum dot with almost degenerate spin-singlet and triplet states for an even number of electrons. We show that the Kondo temperature as a function of the energy difference between the states Delta…
We investigate theoretically the transport properties of the side-coupled double quantum dots in connection with the experimental study of Sasaki {\it et al.} Phys.Rev.Lett.{\bf 103}, 266806 (2009). The novelty of the set-up consists in…
We analyze the transport properties of a double quantum dot device in the side-coupled configuration. A small quantum dot (QD), having a single relevant electronic level, is coupled to source and drain electrodes. A larger QD, whose…
We investigate the Kondo effect in a double-quantum-dot which is capacitively coupled to a charge-Qubit. It is shown that due to this capacitive coupling, the bare inter-dot repulsive interaction in the double-quantum-dot is effectively…
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 electric and thermoelectric transport properties of correlated quantum dots coupled to two ferromagnetic leads and one superconducting electrode. Transport through such hybrid devices depends on the interplay of…
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…
We investigate the Kondo effect in two-dimensional disordered electron systems using a finite-temperature quantum Monte Carlo method. Depending on the position of a magnetic impurity, the local moment is screened or unscreened by the spin…
We study a quantum dot connected to the bulk by single-mode junctions at almost perfect conductance. Although the average charge $e\langle N \rangle$ of the dot is not discrete, its spin remains quantized: $s=1/2$ or $s=0$, depending…
We predict that an anisotropic charge Kondo effect appears in a triple quantum dot, when the system has two-fold degenerate ground states of (1,1,0) and (0,0,1) charge configurations. Using bosonization and refermionization methods, we find…
We theoretically study enhancement mechanisms of the Kondo effect in multilevel quantum dots. In quantum dots fabricated on semiconductors, the energy difference between discrete levels \Delta is tunable by applying a magnetic field. With…
We study the low-energy properties of a triangular triple quantum dot connected to two non-interacting leads in a wide parameter range, using the numerical renormalization group (NRG). Various kinds of Kondo effects take place in this…
Nonequilibrium electronic transport through a quantum dot coupled to ferromagnetic leads (electrodes) is studied theoretically by the nonequilibrium Green function technique. The system is described by the Anderson model with arbitrary…
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…
We investigate the effects induced by spin polarization in the contacts attached to a serial double quantum dot. The polarization generates effective magnetic fields and suppresses the Kondo effect in each dot. The super-exchange…
Molecular electronics offers unique scientific and technological possibilities, resulting from both the nanometre scale of the devices and their reproducible chemical complexity. Two fundamental yet different effects, with no classical…
The effective interaction between magnetic impurities in metals that can lead to various magnetic ground states often competes with a tendency for electrons near impurities to screen the local moment (Kondo effect). The simplest system…
System of two quantum dots attached to external electrodes is considered theoretically in orbital Kondo regime. In general, the double dot system is coupled via both Coulomb interaction and direct hoping. Moreover, the indirect hopping…