Related papers: Demonstration of Open Quantum System Optimal Contr…
The efficiency of dipole-dipole coupling driven coherence transfer experiments in solid-state NMR spectroscopy of powder samples is limited by dispersion of the orientation of the internuclear vectors relative to the external magnetic…
An electron confined in a quantum dot interacts with its local nuclear spin environment through the hyperfine contact interaction. This interaction combined with external control and relaxation or measurement of the electron spin allows for…
For the model Hamiltonian describing the electron-nuclear dynamics of a quantum dot, we obtained an exact expression for the limiting nuclear polarization as a function of the number of groups of equivalent nuclei. It is shown that the…
We investigate in micro-photoluminescence experiments the dynamical nuclear polarization in individual InGaAs quantum dots. Experiments carried out in an applied magnetic field of 2T show that the nuclear polarization achieved through the…
The nature of the nano-scale environment presents a major challenge for solid-state implementation of spin-based qubits. In this work, a single electron spin in an optically pumped nanometer-sized III-V semiconductor quantum dot is used to…
The polarisation dynamics of nuclear spins weakly coupled to an NV center is highly sensitive to the parameters of the microwave control and the nuclear Larmor frequency. What is commonly regarded as a challenge, we propose here as a…
We report on the dynamic nuclear polarization of a single charge-tunable self-assembled InAs/GaAs quantum dot in a longitudinal magnetic field of $\sim$0.2T. The hyperfine interaction between the optically oriented electron and nuclei spins…
The ability to sense and control nuclear spins near solid-state defects might enable a range of quantum technologies. Dynamically Decoupled Radio-Frequency (DDRF) control offers a high degree of design flexibility and long electron-spin…
Laser induced ultrafast demagnetization is the process whereby the magnetic moment of a ferromagnetic material is seen to drop significantly on a timescale of $10-100$s of femtoseconds due to the application of a strong laser pulse. If this…
Several efforts have been made to polarize the nearby nuclear environment of nitrogen vacancy (NV) centers for quantum metrology and quantum information applications. Different methods showed different nuclear spin polarization efficiencies…
Optically-pumped color centers in semiconductor powders can potentially induce high levels of nuclear spin polarization in surrounding solids or fluids at or near ambient conditions, but complications stemming from the random orientation of…
A theoretical study of spin dynamics in non-relativistic particle beams with interacting angular momenta traversing static, spatially varying magnetic fields is presented. The computational framework evaluates sinusoidal magnetic field…
Optical pump-probe techniques are used to generate and measure electron spin polarization in a gallium arsenide epilayer in which the electron spin coherence time exceeds the mode-locked laser repetition period. Resonant spin amplification…
We report the observation of a feedback process between the nuclear spins in a single charged quantum dot and its trion transition, driven by a periodic sequence of optical pulses. The pulse sequence intersperses off-resonant ultrafast…
Highly polarized nuclear spins within a semiconductor quantum dot (QD) induce effective magnetic (Overhauser) fields of up to several Tesla acting on the electron spin or up to a few hundred mT for the hole spin. Recently this has been…
We describe how a local non-equilibrium nuclear polarisation can be generated and detected by electrical means in a semiconductor quantum point contact device. We show that measurements of the nuclear spin relaxation rate will provide clear…
Spontaneous nuclear polarization is predicted in double quantum dots in the spin-blocked electron transport regime. The polarization results from an instability of the zero-polarization state when singlet and triplet electron energy levels…
Due to their long coherence times, nuclear spins have gained considerable attention as physical qubits. Two-qubit gates between nuclear spins of distinct resonance frequencies can be mediated by electron spins, usually employing a sequence…
PulsePol is an elegantly designed pulse-sequence-based quantum control scheme that enables polarization transfer between electron and nuclear spins, for example, in nitrogen-vacancy (NV) centers. However, previous analyses of PulsePol…
Work within this thesis advances optimal control algorithms for application to magnetic resonance systems. Specifically, presenting a quadratically convergent version of the gradient ascent pulse engineering method. The work is formulated…