Related papers: Kondo effect and spin filtering in coupled quantum…
We study an orbitally degenerate Kondo effect in a triangular triple quantum dot (TTQD), where the three dots are connected vertically with a single metallic lead through electron tunneling. Both spin and orbital degrees of freedom play an…
Quantum dots in the quantum Hall regime can have pairs of single Slater determinant states that are degenerate in energy. We argue that these pairs of many body states may give rise to a Kondo effect which can be mapped into an ordinary…
Single electron tunneling is studied in a many electron quantum dot in high magnetic fields. For such a system multiple transitions of the spin configuration are theoretically predicted. With a combination of spin blockade and Kondo effect…
We present the transport properties of a strongly correlated quantum dot attached to two leads with a side coupled non-interacting quantum dot. Transport properties are analyzed using the slave boson mean field theory which is reliable in…
Kondo correlation in a spin polarized quantum dot (QD) results from the dynamical formation of a spin singlet between the dot's net spin and a Kondo cloud of electrons in the leads, leading to enhanced coherent transport through the QD. We…
A new theoretical method is introduced to study coherent electron transport in an interacting multilevel quantum dot. The method yields the correct behavior both in the limit of weak and strong coupling to the leads, giving a unified…
The $SU(4)-SU(2)$ crossover, driven by an external magnetic field $h$, is analyzed in a capacitively-coupled double-quantum-dot device connected to independent leads. As one continuously charges the dots from empty to quarter-filled, by…
We report Kondo-like behaviour in a quantum antidot (a submicron depleted region in a two-dimensional electron gas) in the quantum-Hall regime. When both spin branches of the lowest Landau level encircle the antidot in a magnetic field…
The Kondo effect is a striking consequence of the coupling of itinerant electrons to a quantum spin with degenerate energy levels. While degeneracies are commonly thought to arise from symmetries or fine-tuning of parameters, the recent…
We present transport measurements of the Kondo effect in a double quantum dot charged with only one or two electrons, respectively. For the one electron case we observe a surprising quasi-periodic oscillation of the Kondo conductance as a…
Transport properties in the Kondo regime of a nanosystem displaying uniaxial magnetic anisotropy (such as a magnetic molecule, magnetic adatom or quantum dot coupled to a localized magnetic moment) are analyzed theoretically. In particular,…
The magnetic field dependence of the average spin of a localized electron coupled to conduction electrons with an antiferromagnetic exchange interaction is found for the ground state. In the magnetic field range $\mu H\sim 0.5 T_c$ ($T_c$…
We investigate Kondo correlations in a quantum dot with normal and superconducting electrodes, where a spin bias voltage is applied across the device and the local interaction $U$ is either attractive or repulsive. When the spin current is…
Quantum spin transport is studied in an interacting quantum dot. It is found that a conductance "plateau" emerges in the non-linear charge conductance by a spin bias in the Kondo regime. The conductance plateau, as a complementary to the…
We investigate the paramagnetic periodic Anderson model using the dynamical mean-field theory in combination with the modified perturbation theory which interpolates between the weak and strong coupling limits. For the symmetric PAM, the…
A quadruple quantum-dot (QQD) cell is proposed as a spin filter. The transport properties of the QQD cell were studied in linear response regime on the basis of the equations of motion for retarded Green's functions. The developed approach…
We investigate the persistent current influenced by the spin fluctuations in a mesoscopic ring weakly coupled to a quantum dot. It is shown that the Kondo effect gives rise to some unusual features of the persistent current in the limit…
The Kondo divergences owing to interaction of current carriers with local moments in highly correlated electron systems are considered within the Hubbard and s-d exchange models with infinitely strong on-site interaction, the many-electron…
A triangular triple quantum dot gives various Kondo effects, such as the emergence of an electric polarization accompanied by a complete compensation of spin degrees of freedom. The interplay of spin and charge of electrons in quantum dots…
We demonstrate that in a single molecule magnet (SMM) strongly coupled to electrodes the Kondo effect involves all magnetic excitations. This Kondo effect is induced by the quantum tunneling of the magnetic moment (QTM). Importantly, the…