Related papers: Symmetry causes a huge conductance peak in double …
We theoretically investigate transport signatures of quantum interference in highly symmetric double quantum dots in a parallel geometry and demonstrate that extremely weak symmetry-breaking effects can have a dramatic influence on the…
We present measurements of transport through two tunnel-coupled quantum dots of different sizes connected in series in a strong, variable, perpendicular magnetic field. Double dot conductance was measured both as a function of magnetic…
It was proposed that a double quantum dot can be used to be a detector of spin bias. Electron transport through a double quantum dot is investigated theoretically when a pure spin bias is applied on two conducting leads contacted to the…
Indirect exchange interaction between itinerant electrons and nano-structures with non-trivial geometrical configurations manifests a plethora of unexpected results. These configurations can be realized either in quantum dots with several…
We apply the semiclassical theory of transport to quantum dots with exact and approximate spatial symmetries; left-right mirror symmetry, up-down mirror symmetry, inversion symmetry or four-fold symmetry. In this work - the first of a pair…
By means of an envelope function analysis, we perform a numerical investigation of the conductance behavior of a graphene structure consisting of two regions (dots) connected to the entrance and exit leads through constrictions and…
Quasi-static transport measurements are employed on a laterally defined tunnel-coupled double quantum dot. A nearby quantum point contact allows us to track the charge as added to the device. If charged with only up to one electron, the…
We show that 2D gapped many-body quantum states are constrained by an infinite-dimensional symmetry which renders them transparent to weak disorder. This prevents disorder-induced localization when interactions are strong enough to open a…
The effect of the barrier on the proximity effect in normal-superconductor junction is analyzed. A general criterion for the barrier, though large, to be effectively transparent, is given. This criterion is applied to both the conductance…
The conductance of systems containing two tunnel point-contacts and a single subsurface scatterer is investigated theoretically. The problem is solved in the approximation of s-wave scattering giving analytical expressions for the wave…
We investigate the phenomenon of reflectionless tunneling in ballistic normal-metal--superconductor (NS) structures, using a semiclassical formalism. It is shown that applied magnetic field and superconducting phase difference both impair…
We have investigated theoretically the conductance of a Normal-Superconductor point-contact in the tunnel limit and analyzed the quantum interference effects originating from the scattering of quasiparticles by point-like defects.…
Tunneling conductance through two quantum dots, which are connected in series to left and right leads, is calculated by using the numerical renormalization group method. As the hopping between the dots increases from very small value, the…
Experiments on hybrid superconducting normal-metal structures have revealed that even in the absence of tunnel junctions the onset of superconductivity can lead to a decrease in the electrical conductance by an amount many orders of…
In the presence of time-reversal symmetry, quantum interference gives strong corrections to the electric conductivity of disordered systems. The self-interference of an electron wavefunction traveling time-reversed paths leads to effects…
We study electron tunneling through two small ferromagnetic dots. Quantum charge fluctuations and interdot coupling make each Coulomb peak of the conductance at zero interdot coupling split across. The interdot tunnel coupling is determined…
Planar macroscopic magnetic tunnel junctions exhibit well defined zero bias anomalies when a thin layer of ferromagnetic CoFe(B) nanodots is inserted within a MgO based tunnel barrier. The conductance curves exhibit a single and a double…
The interaction between particles and the electromagnetic field induces decoherence generating a small suppression of fringes in an interference experiment. We show that if a double slit--like experiment is performed in the vicinity of a…
We present lateral transport measurements on strongly, vertically coupled quantum dots formed in separate quantum wells in a GaAs/AlGaAs heterostructure. Coulomb oscillations are observed forming a honeycomb lattice consistent with two…
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$_2$…