Related papers: Localized charge bifurcation in the coupled quantu…
We study the Kondo effect in side-coupled double quantum dots with particular focus on the crossover between two distinct singlet ground states, using the numerical renormalization group. The crossover occurs as the quantized energy level…
Charge sensing in quantum-dot structures is studied by an exactly solvable reduced model and numerical density-matrix renormalization group methods. Charge sensing is characterized by the repeated cycling of the occupation of…
We report measurements of a tunable double quantum dot, operating in the quantum regime, with integrated local charge sensors. The spatial resolution of the sensors is sufficient to allow the charge distribution within the double dot system…
We report here on a direct and non-invasive measurement of the charge and its distribution in a Kondo correlated quantum dot (QD). A non-invasive potential-sensitive detector in proximity with the QD reveals that even though the conductance…
We study the loading of electrons into a quantum dot with dynamically controlled tunnel barriers. We introduce a method to measure tunneling rates for individual discrete states and to identify their relaxation paths. Exponential…
We present the results of theoretical studies on operations with charge qubits in the system composed of two tunnel-coupled semiconductor quantum dots whose two lowest states (localized in different dots) define the logical qubit states…
We investigate theoretically the entanglement of two quantum dots (QDs) coupled to metallic nanowaveguide in the presence of the flip-flop interaction with the analytical solutions of eigenvalue equations of the coupled system. High…
We present real-time detection measurements of electron tunneling in a graphene quantum dot. By counting single electron charging events on the dot, the tunneling process in a graphene constriction and the role of localized states are…
We study acoustic-phonon-induced relaxation of charge excitations in single and tunnel-coupled quantum dots containing few confined interacting electrons. The Full Configuration Interaction approach is used to account for the…
We present a numerical model which allows us to study the Kelvin force probe microscopy response to the charge switching in quantum dots at various time scales. The model provides more insight into the behavior of frequency shift and…
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…
The detection of the quantum dot charge state using a quantum point contact charge detector has opened a new exciting route for the investigation of quantum dot devices in recent years. In particular, time-resolved charge detection allowed…
We theoretically investigate the robustness of cluster states in charge qubit system based on quantum dot (QD) and double quantum point contact (DQPC). Trap state is modeled by an island structure in DQPC and represents a dynamical…
We investigate the electronic transport through two parallel double quantum dots coupled both capacitively and via a perpendicularly aligned charge qubit. The presence of the qubit leads to a modification of the coherent tunnel amplitudes…
We study the steady-state current in a minimal model for a quantum dot dominated by charge fluctuations and analytically describe the time evolution into this state. The current is driven by a finite bias voltage V across the dot, and two…
We have observed anomalous transport properties for a 50 nm Bi dot in the Coulomb-blockade regime. Over a range of gate voltages, Coulomb blockade peaks are suppressed at low bias, and dramatic structure appears in the current at higher…
We show that two electrons confined in a square semiconductor quantum dot have two isolated low-lying energy eigenstates, which have the potential to form the basis of scalable computing elements (qubits). Initialisation, one-qubit and…
Coupled quantum dots are potential candidates for qubit systems in quantum computing. We use a non-invasive voltage probe to study the evolution of a coupled dot system from a situation where the dots are coupled to the leads to a situation…
We investigate transport through an exotic ``charge'' qubit composed of two strongly capacitively coupled quantum dots (QDs), each being independently connected to a side gate which in general exhibits a fluctuating electrostatic field…
A double quantum dot charge detector, with one dot Coulomb coupled to the electron to be detected and the other modulated by a time-dependent plunger voltage, is analyzed in a minimal model. The signal and noise of the detector are…