Related papers: Zero-bias conductance in carbon nanotube quantum d…
The connection of electrical leads to wire-like molecules is a logical step in the development of molecular electronics, but also allows studies of fundamental physics. For example, metallic carbon nanotubes are quantum wires that have been…
Electronic transport properties of bismuth nanocontacts are analyzed by means of a low temperature scanning tunneling microscope. The subquantum steps observed in the conductance versus elongation curves give evidence of atomic…
We report on the preparation of carbon nanotube quantum dots using superconducting electrodes made of niobium. Gate-controllable supercurrents with values of up to 30 nA are induced by the proximity effect. The IV-curves are hysteretic at…
We calculate the conductance through a single quantum dot coupled to metallic leads, modeled by the spin 1/2 Anderson model. We adopt the finite-U extension of the noncrossing approximation method. Our results are in good agreement with…
We report on two top-gate defined, coupled quantum dots in a semiconducting single wall carbon nanotube, constituting a tunable double quantum dot system. The single wall carbon nanotubes are contacted by titanium electrodes, and gated by…
We revisit correlation effects in doped metallic zigzag carbon nanotubes by using both the one-loop renormalization group and non-perturbative bosonization techniques. Note that, if a nanotube is placed near a conducting plate, the…
We present a study on the mechanical configuration and the electronic properties of semiconducting carbon nanotubes supported by partially depassivated silicon substrates, as inferred from topographic and spectroscopic data acquired with a…
We consider a double dot system of equivalent, capacitively coupled semiconducting quantum dots, each coupled to its own lead, in a regime where there are two electrons on the double dot. Employing the numerical renormalization group, we…
Adsorption of 1/3 monolayer of Sn on a heavily-doped p-type Si(111) substrate results in the formation of a hole-doped Mott insulator, with electronic properties that are remarkably similar to those of the high-Tc copper oxide compounds. In…
It is shown that the resonance Kondo tunneling through a double quantum dot (DQD) with even occupation and singlet ground state may arise at a strong bias, which compensates the energy of singlet/triplet excitation. Using the…
We have measured the differential conductance dI/dV of individual multi-wall carbon nanotubes (MWNT) of different lengths. A cross-over from wire-like (long tubes) to dot-like (short tubes) behavior is observed. dI/dV is dominated by random…
The nonlinear conductance of semiconductor heterostructures and single molecule devices exhibiting Kondo physics has recently attracted attention. We address the observed sample dependence of the measured steady state transport coefficients…
We calculate the current and electrostatic potential drop in metallic carbon nanotube wires self-consistently, by solving the Green's function and electrostatics equations in the ballistic case. About one tenth of the applied voltage drops…
Using nonequilibrium Green functions and several complementary many-body approximations we calculate shot noise and spin dependent conductance in carbon nanotube semiconducting quantum dot in spin-orbital Kondo regime. We point out on the…
The Kondo effect and superconductivity are both prime examples of many-body phenomena. Here we report transport measurements on a carbon nanotube quantum dot coupled to superconducting leads that show a delicate interplay between both…
The tunneling conductance is calculated as a function of the gate voltage in wide temperature range for the single quantum dot systems with Coulomb interaction. We assume that two orbitals are active for the tunneling process. We show that…
A theoretical analysis of the superconductivity observed recently in Carbon nanotubes is proposed. We argue that ultra-small (diameter $ \sim 0.4 nm$) single wall carbon nanotubes (with transition temperature $T_c\sim 15 ^{o}K$) and…
Quantum dots defined in carbon nanotubes are a platform for both basic scientific studies and research into new device applications. In particular, they have unique properties that make them attractive for studying the coherent properties…
Most quantum point contacts (QPCs) fabricated in high-mobility 2D electron gases show a zero-bias conductance peak near pinchoff, but the origin of this peak remains a mystery. Previous experiments have primarily focused on the zero-bias…
We study the Coulomb interaction effects on the tunneling conductance of a contact constructed of two parallel quantum wires. The following contacts are considered: two clean identical quantum wires, two disordered identical quantum wires,…