Related papers: An electrostatically defined serial triple quantum…
Time-resolved electron dynamics in coupled quantum dots is directly observed by a pulsed-gate technique. While individual gate voltages are modulated with periodic pulse trains, average charge occupations are measured with a nearby quantum…
Tunneling excitations of electrons in dry-etched modulation-doped AlGaAs/GaAs coupled quantum dots (QDs) are probed by resonant inelastic light scattering. A sequence of intra- and intershell excitations are found at energies determined by…
With non-invasive methods, we investigate ground and excited states of a lateral quantum dot. Charge detection via a quantum point contact is used to map the dot dynamics in a regime where the current through the dot is too low for…
Quantum dots must be tuned precisely to provide a suitable basis for quantum computation. A scalable platform for quantum computing can only be achieved by fully automating the tuning process. One crucial step is to trap the appropriate…
We study the nonequilibrium properties of an electronic circuit composed of a double quantum dot (DQD) channel coupled to a quantum point contact (QPC) within the framework of stochastic thermodynamics. We show that the transition rates…
We predict large regions of the charge stability diagram using a multi-band and multi-electron configuration interaction model of a double quantum dot system. We account for many-body interactions within each quantum dot using full…
We propose a quantum transport experiment to prepare and measure charge-entanglement between two electrostatically defined quantum dots. Coherent population trapping, as realized in cavity quantum electrodynamics, can be carried out by…
Quantum dots (QD) with electric-field-controlled charge state are promising for electronics applications, e.g., digital information storage, single-electron transistors and quantum computing. Inorganic QDs consisting of semiconductor…
Strong confinement of charges in few electron systems such as in atoms, molecules and quantum dots leads to a spectrum of discrete energy levels that are often shared by several degenerate quantum states. Since the electronic structure is…
We report on the realization of a coupled quantum dot (QD) system containing two single QDs made in two adjacent InAs nanowires. One QD (sensor QD) is used as a charge sensor to detect the charge state transition in the other QD (target…
Non-adiabatic pumping of discrete charges, realized by a dynamical quantum dot in an AlGaAs/GaAs heterostructure, is studied under influence of a perpendicular magnetic field. Application of an oscillating voltage in the GHz-range to one of…
We present a theory of quantum circuits based on logical qubits encoded in chirality of electron spin complexes in lateral gated semiconductor triple quantum dot molecules with one electron spin in each dot. Using microscopic Hamiltonian we…
We present a unified theory of quantum phase transitions for half-filled quantum dots (QDs) coupled to gapped host bands. We augment the bands by additional weakly coupled metallic lead which allows us to analyze the system by using…
We consider a triple quantum dot system in a triangular geometry with one of the dots connected to metallic leads. Using Wilson's numerical renormalization group method, we investigate quantum entanglement and its relation to the…
We present a formulation of Quantum Electrodynamics in terms of an antisymmetric tensor gauge field. In this formulation the topological current of this field appears as a source for the electromagnetic field and the topological charge…
Recent advances in nanotechnology have enabled researchers to manipulate small collections of quantum mechanical objects with unprecedented accuracy. In semiconductor quantum dot qubits, this manipulation requires controlling the dot…
We demonstrate a novel method for measuring the discrete energy spectrum of a quantum dot connected very weakly to a single lead. A train of voltage pulses applied to a metal gate induces tunneling of electrons between the quantum dot and a…
We observe the low-lying excitations of a molecular dimer formed by two electrons in a GaAs semiconductor quantum dot in which the number of confined electrons is tuned by optical illumination. By employing inelastic light scattering we…
Quantum dots (QDs) are pivotal for the development of quantum technologies, with applications ranging from single-photon sources for secure communication to quantum computing infrastructures. Understanding the electron dynamics within these…
We demonstrate a hole double quantum dot in an undoped GaAs/AlGaAs heterostructure. The interdot coupling can be tuned over a wide range, from formation of a large single dot to two well-isolated quantum dots. Using charge sensing, we show…