Related papers: Correlation between lasing and transport propertie…
Quantum state tomography is an important tool in quantum information science for complete characterization of multi-qubit states and their correlations. Here we report a method to perform a joint simultaneous read-out of two superconducting…
Strong correlation effects on electron transport through a spinless quantum dot are considered. When two single-particle levels in the quantum dot are degenerate, a conserved pseudospin degree of freedom appears for general tunneling matrix…
We have investigated the transport characteristics of an electron pump consisting of an asymmetric double quantum dot at zero bias voltage which is subject to electromagnetic radiation. Depending on the energies of the intermediate states…
An interaction of electromagnetic field with a nanostructure composed of two quantum dots is studied theoretically. An effect of a resonant electron transfer between the localized low-lying states of quantum dots is predicted. A necessary…
Nonequilibrium properties of correlated quantum matter are being intensively investigated because of the rich interplay between external driving and the many-body correlations. Of particular interest is the nonequilibrium behavior near a…
Off-resonance conductance through weakly coupled quantum dots ("valley conductance") is governed by cotunneling processes in which a large number of dot states participate. Virtually the same states participate in the transport at…
We consider a lateral double-dot system in the Coulomb blockade regime with a single spin-1/2 on each dot, mutually coupled by an anti-ferromagnetic exchange interaction. Each of the two dots is contacted by two leads. We demonstrate that…
We study the dynamical multistability of a solid-state single-atom laser implemented in a quantum-dot spin valve. The system is formed by a resonator that interacts with a two-level system in a dot in contact with two ferromagnetic leads of…
Various causes for negative differential conductance in transport through an interacting double quantum dot are investigated. Particular focus is given to the interplay between the renormalization of the energy levels due to the coupling to…
Electronic transport through a triple quantum dot system, with only a single dot coupled directly to external leads, is considered theoretically. The model includes Coulomb correlations in the central dot, while such correlations in the two…
The interplay between the Kondo effect and the inter-dot magnetic interaction in a coupled-dot system is studied. An exact result for the transport properties at zero temperature is obtained by diagonalizing a cluster, composed by the…
This thesis is devoted to the study of quantum mechanical effects that arise in systems of reduced dimensionality. Specifically, we investigate coherence and correlation effects in quantum transport models. In the first part, we present a…
Achieving simultaneous lasing of photons and phonons in optomechanical setups has great potential for applications in quantum information processing, high precision sensing and the design of hybrid photonic-phononic devices. Here, we…
A few electron double electrostatic lateral quantum dot can be transformed into a few electron triple quantum dot by applying a different combination of gate voltages. Quadruple points have been achieved at which all three dots are…
We report on electrical transport measurements through a carbon nanotube quantum dot coupled to a normal and a superconducting lead. The ratio of Kondo temperature and superconducting gap $T_{K}/\Delta$ is identified to govern the transport…
We study the electronic transport in a double quantum dot structure connected to leads in the Kondo regime for both series and parallel arrangements. By applying a finite-U slave boson technique in the mean field approximation we explore…
The coherence between quantum states with different particle numbers --- the Fock-space coherence --- qualitatively differs from the more common Hilbert-space coherence between states with equal particle numbers. For a quantum dot with…
Electron transport through a double quantum dot system is studied with taking into account electron-phonon interaction. The Keldysh nonequilibrium Green function formalism is used to compute the current and transmission coefficient of the…
Coupling a quantum system to a bosonic environment always give rise to inelastic processes, which reduce the coherency of the system. We measure energy dependent rates for inelastic tunneling processes in a fully controllable two-level…
We study a system consisting of a superconducting flux qubit strongly coupled to a microwave cavity. Externally applied qubit driving is employed in order to manipulate the spectrum of dressed states. We observe resonance narrowing in the…