Related papers: Unhiding a concealed resonance by multiple Kondo t…
In this work we analyze the nonequilibrium transport through a quantum impurity (quantum dot or molecule) attached to ferromagnetic leads by using a hybrid numerical renormalization group-time-dependent density matrix renormalization group…
Tunnelling conductances observed for mesoscopic Kondo systems exhibit a zero-bias peak and two coherent side peaks. The former peak is usually understood as a Kondo effect and the latter side peak is recently clarified as the effect of…
We have studied low-temperature single electron transport through ultra-small Si quantum dots. We find that at low temperatures Coulomb blockade is partially lifted at certain gate voltages. Furthermore, we observed an enhancement of…
Motivated by recent experimental observation of spin-orbit coupling in carbon nanotube quantum dots [F. Kuemmeth \textsl{et al.}, Nature (London) {\bf 452}, 448 (2008)], we investigate in detail its influence on the Kondo effect. The…
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…
Spin polarized transport through a quantum dot coupled to ferromagnetic electrodes with noncollinear magnetizations is discussed in terms of nonequilibrium Green functions formalism in the finite-U slave boson mean field approximation. The…
High quality single wall carbon nanotube quantum dots have been made showing both metallic and semiconducting behavior. Some of the devices are identified as small band gap semiconducting nanotubes with relatively high broad conductance…
We review the mechanisms of low-temperature electron transport across a quantum dot weakly coupled to two conducting leads. Conduction in this case is controlled by the interaction between electrons. At temperatures moderately lower than…
Spin-polarized transport through quantum dots is analyzed theoretically in the cotunneling regime. It is shown that the zero-bias anomaly, found recently in the antiparallel configuration, can also exist in the case when one electrode is…
We investigate the equilibrium and out-of-equilibrium Kondo effects in a single-level interacting quantum dot connected to two ferromagnetic leads. Within the non-crossing approximation, we calculate the total density of states (DOS), the…
We analyzed the effects of a spin voltage as well as a conventionally applied voltage in a QD system with a different number of quantum states in the dot region in presence of Coulombic interaction between the quantum dot and two leads. We…
We study the differential conductance in the Kondo regime of a quantum dot coupled to multiple leads. When the bias is applied symmetrically on two of the leads ($V$ and $-V$, as usual in experiments), while the others are grounded, the…
We investigate quantum dots in clean single-wall carbon nanotubes with ferromagnetic PdNi-leads in the Kondo regime. In most odd Coulomb valleys the Kondo resonance exhibits a pronounced splitting, which depends on the tunnel coupling to…
We describe linear and nonlinear transport across a single impurity Anderson model quantum dot with intermediate coupling to the leads, i.e., with tunnel coupling of the order of the thermal energy k_B T. The coupling is large enough that…
We have studied electron transport in clean single-walled carbon nanotube quantum dots. Because of the large number of Coulomb blockade diamonds simultaneously showing both shell structure and Kondo effect, we are able to perform a detailed…
We analyze the equilibrium transport properties of underscreened Kondo effect in the case of a two-level quantum dot coupled to ferromagnetic leads. Using the numerical renormalization group (NRG) method, we have determined the gate voltage…
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 report on the observation of Kondo and split Kondo peaks in single-molecule transistors containing a single spin transition molecule with a Fe2+ ion. Coulomb blockade characteristics reveal a double quantum dot behavior in a parallel…
We study the nonequilibrium spin transport through a quantum dot containing two spin levels coupled to the magnetic electrodes. A formula for the spin-dependent current is obtained and is applied to discuss the linear conductance and…
We study resonant tunneling through an interacting quantum dot coupled to normal metallic and superconducting leads. We show that large Coulomb interaction gives rise to novel effects in Andreev transport. Adopting an exact relation for the…