Related papers: Efficient exciton generation in a semiconductor qu…
Semiconductor quantum dots can emit antibunched, single photons on demand with narrow linewidths. However, the observed linewidths are broader than lifetime measurements predict, due to spin and charge noise in the environment. This noise…
Spatially structured light fields applied to semiconductor quantum dots yield fundamentally different absorption spectra than homogeneous beams. In this paper, we theoretically discuss the resulting spectra for different light beams using a…
Narrow line-widths and the possibility of enhanced spontaneous emission via coupling to microcavities make semiconductor quantum dots ideal for harnessing coherent quantum phenomena at the single photon level. So far, however, all…
We describe how quantum dot semiconductor cavity systems can be engineered to realize anisotropy-induced dipole-dipole coupling between orthogonal dipole states in a single quantum dot. Quantum dots in single-mode cavity structures as well…
We present a continuous-time, neural-network-based approach to optimal control in quantum systems, with a focus on pulse engineering for quantum gates. Leveraging the framework of neural ordinary differential equations, we construct control…
The cluster state quantum computation is a versatile approach to build a scalable quantum computer. In this thesis we theoretically demonstrate that a one dimensional array of double quantum dots with long spin relaxation time can evolve to…
Combining the capabilities of gate defined quantum transport devices in GaAs-based heterostructures and of optically addressed self-assembled quantum dots could open broad perspectives for new devices and functionalities. For example,…
The signature of coherent coupling between two quantum states is an anticrossing in their energies as one is swept through the other. In single semiconductor quantum dots containing an electron-hole pair the eigenstates form a two-level…
Composite pulses provide a simple means for constructing quantum logic gates which are robust to small errors in the control fields used to implement them. Here I describe how antisymmetric composite NOT gates can be nested to produce gates…
We present a theory of highly excited interacting carriers confined in a semiconductor nanostructure, incorporating Auger coupling between excited states with different number of excitations. The Coulomb matrix elements connecting exciton,…
A computational model is presented to calculate the ground state energy of neutral and charged excitons confined in semiconductor quantum dots. The model is based on the variational Quantum Monte Carlo method and effective mass…
Optically-controlled exciton dynamics in coupled quantum dots is studied. We show that the maximally entangled Bell states and Greenberger-Horne-Zeilinger (GHZ) states can be robustly generated by manipulating the system parameters to be at…
We introduce a novel control method for robust quantum information processing suited for quantum integrated photonics. We utilize off-resonant detunings as control parameters to derive a new family of composite pulses for high-fidelity…
Similar to atoms and nuclei, semiconductor quantum dots exhibit formation of shells. Predictions of magnetic behavior of the dots are often based on the shell occupancies. Thus, closed-shell quantum dots are assumed to be inherently…
In a semiconductor quantum dot, the Px and Py transitions to the polarization eigenstates, |x> and |y>, naturally form a three-level V-type system. Using low-temperature polarized photoluminescence spectroscopy, we have investigated the…
Since the first demonstration of coherent control of a quantum state of a superconducting charge qubit a variety of Josephson-junction-based qubits have been implemented with remarkable progress in coherence time and read-out schemes.…
We introduce a hybrid qubit based on a semiconductor nanowire with an epitaxially grown superconductor layer. Josephson energy of the transmon-like device ("gatemon") is controlled by an electrostatic gate that depletes carriers in a…
In this paper, we experimentally demonstrate an oscillating energy shift of quantum-confined exciton levels in a semiconductor quantum well after excitation into a superposition of two quantum confined exciton states of different parity.…
Quantum dots are nanostructures made of semiconducting materials that are engineered to hold a small amount of electric charge (a few electrons) that is controlled by external gate and may hence be considered as tunable artificial atoms. A…
It is demonstrated how the exciton and the biexciton state of a quantum dot can be prepared with high fidelity on a picosecond time-scale by driving the dot with a strong laser pulse that is tuned above the exciton resonance for exciton…