Related papers: Cotunneling effects in GaAs vertical double quantu…
By using bosonization method and unitary transformation, we give a general relation between the dimensionless tunneling conductance and the fractional Coulomb blockade conductance peak splitting which is valid both for weak and strong…
We report measurements of mesoscopic fluctuations of elastic cotunneling in Coulomb blockaded quantum dots. Unlike resonant tunneling on Coulomb peaks, cotunneling in the valleys is sensitive to charging effects. We observe a larger…
We explore the finite bias DC differential conductance of a correlated quantum dot under the influence of an AC field, from the low-temperature Kondo to the finite temperature Coulomb blockade regime. Real-time simulations are performed…
We investigate the figure of merit of a quantum dot (QD) in the Coulomb blockade regime. It is found that the figure of merit $ZT$ may be quite high if only single energy level in the QD is considered. On the other hand, with two or multi…
We consider the proximity effect in a normal dot coupled to a bulk superconducting reservoir by the tunnel contact with large normal conductance. Coulomb interaction in the dot suppresses the proximity minigap induced in the normal part of…
We present comparative measurements of the charge occupation and conductance of a GaAs/AlGaAs quantum dot. The dot charge is measured with a capacitively coupled quantum point contact sensor. In the single-level Coulomb blockade regime near…
A system consisting of two independently contacted quantum dots with strong electrostatic interaction shows interdot Coulomb blockade when the dots are weakly tunnel coupled to their leads. It is studied experimentally how the blockade can…
The temperature dependence of the I-V characteristics of many single-electron tunneling devices enable thermometer operation of these systems. We investigate two normal conducting kinds of them, {\sl (a)} a single junction in a…
Recently, it has been shown that magnetic tunnel junctions with thin MgO tunnel barriers exhibit extraordinarily high tunneling magnetoresistance (TMR) values at room temperature1, 2. However, the physics of spin dependent tunneling through…
Low-temperature transport properties of a lateral quantum dot formed by overlaying finger gates in a clean one-dimensional channel are investigated. Continuous and periodic oscillations superimposed upon ballistic conductance steps are…
We report the fabrication and characterization of gate-defined hole quantum dots in monolayer and bilayer WSe$_2$. The devices were operated with gates above and below the WSe$_2$ layer to accumulate a hole gas, which for some devices was…
In the ring-shaped tunnel-junction array with four islands, the secondary Coulomb blockade gap in a low bias-voltage range is observed in the I-V characteristics. We attribute its appearance to the unique topology of the array which induces…
We study the Coulomb pseudogap for tunneling into the two-dimensional electron system of high-mobility (Al,Ga)As/GaAs heterojunctions subjected to a quantizing magnetic field at filling factor $\nu \leq 1$. Tunnel current-voltage…
We investigate non-equilibrium transport properties of a quantum dot in the Coulomb blockade regime under the condition of negligible inelastic scattering during the dwelling time of the electrons in the dot. Using the quantum kinetic…
We investigate cross-correlations in the tunneling currents through two parallel quantum dots coupled to independent electrodes and gates and interacting via an inter-dot Coulomb interaction. The correlations reveal additional information,…
We combine electrostatic and magnetic confinement to define a quantum dot in bilayer graphene. The employed geometry couples $n$-doped reservoirs to a $p$-doped dot. At magnetic field values around $B = 2~$T, Coulomb blockade is observed.…
We report the low temperature current-voltage (I-V) characteristics studies in quasi-one dimensional conducting polymer nanofibers. We find a threshold voltage Vt below which little current flows at temperatures below 30-40 K. For V > Vt…
We report transport measurements on a semiconductor quantum dot with a small number of confined electrons. In the Coulomb blockade regime, conduction is dominated by cotunneling processes. These can be either elastic or inelastic, depending…
We study the dependence of the Kondo temperature on the gate voltage in a strongly blockaded quantum dot with a small single-particle level spacing. We show that the dependence cannot be fitted to that of the Anderson impurity model with…
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…