Related papers: Few-electron spin qubits in optically active GaAs …
We investigate experimentally and theoretically few-particle effects in the optical spectra of single quantum dots (QDs). Photo-depletion of the QD together with the slow hopping transport of impurity-bound electrons back to the QD are…
The real-time spin dynamics and the spin noise spectra are calculated for p and n-charged quantum dots within an anisotropic central spin model extended by additional nuclear electric quadrupolar interactions (QC) and augmented by…
A theoretical spin-based scheme for performing a variety of quantum computations is presented. It makes use of an array of multiple identical computer vectors of phosphorus-doped silicon where the nuclei serve as logical qubits and the…
We show both theoretically and experimentally that scanning tunneling spectroscopy (STS) images of semiconductor quantum dots may display clear signatures of electron-electron correlation. We apply many-body tunneling theory to a realistic…
We discuss advantages and limitations of the spin noise spectroscopy for characterization of interacting quantum dot systems on specific examples of individual singly and doubly charged quantum dot molecules (QDMs). It is shown that all the…
Transient current spectroscopy is proposed and demonstrated in order to investigate the energy relaxation inside a quantum dot in the Coulomb blockade regime. We employ a fast pulse signal to excite an AlGaAs/GaAs quantum dot to an excited…
Single nuclear spins in the solid state have long been envisaged as a platform for quantum computing, due to their long coherence times and excellent controllability. Measurements can be performed via localised electrons, for example those…
We use the spin-polarized excitons in a single quantum dot to design optical controls for basic operations in quantum computing. We examine the ultrafast nonlinear optical processes required and use the coherent nonlinear optical responses…
Entanglement generation and detection are two of the most sought-after goals in the field of quantum control. Besides offering a means to probe some of the most peculiar and fundamental aspects of quantum mechanics, entanglement in…
A high-efficiency spin-photon interface is an essential piece of quantum hardware necessary for various quantum technologies. Self-assembled InGaAs quantum dots have excellent optical properties, if embedded into an optical micro-cavity…
We report the realization of a quadruple quantum dot device in a square-like configuration where a single electron can be transferred on a closed path free of other electrons. By studying the stability diagrams of this system, we…
Spectroscopic measurements with low-temperature scanning tunneling microscopes have been used very successfully for studying not only individual atomic or molecular spins on surfaces but also complexly designed coupled systems. The symmetry…
Quantum technologies offer ways to solve certain tasks more quickly, efficiently, and with greater precision than their classical counterparts. Yet substantial challenges remain in the construction of sufficiently error-free and scalable…
We study the optically pumped nuclear spin polarization in a single GaAs/AlGaAs quantum well in the quantum Hall system. We apply resistive detection via the contact hyperfine interaction, which provides high sensitivity and selectivity, to…
We study the spin filling of a semiconductor quantum dot using excited-state spectroscopy in a strong magnetic field. The field is oriented in the plane of the two-dimensional electron gas in which the dot is electrostatically defined. By…
Optically-active solid-state systems such as self-assembled quantum dots, rare-earth ions, and color centers in diamond and SiC are promising candidates for quantum network, computing, and sensing applications. Although the nuclei in these…
We show that detuned optical pulse trains with a modest spectral width can polarize nuclear spins in InAs quantum dots. The pulse bandwidth is large enough to excite a coherent superposition of both electron spin eigenstates in these…
Optical control of the lateral quantum confinement and number of electrons confined in nanofabricated GaAs/AlGaAs quantum dots is achieved by illumination with a weak laser beam that is absorbed in the AlGaAs barrier. Precise tuning of…
We report the realization of an array of four tunnel coupled quantum dots in the single electron regime, which is the first required step toward a scalable solid state spin qubit architecture. We achieve an efficient tunability of the…
Semiconductor hole-spin qubits offer a promising route to quantum computation due to their weak hyperfine interaction, and strong intrinsic spin-orbit coupling enabling electric control of qubits. Scalable architectures, however, require…