Sökresultat

The ability to manipulate spin states with light forms the basis of spin-based photonics. The development of semiconductors with tunable spin properties will enable devices that use spin for information storage, circular polarized light emission, etc. With the recent reports of a chirality-induced spin selectivity (CISS) effect in electrons, the question arises whether structural chirality provide

In this thesis, theoretical studies of the transport properties of three nanoscale systems: one-dimensional (1D) quantum wires (QWRs), zero-dimensional (0D), laterally confined, double-barrier resonant tunnelling structures (DBRTSs) and three-terminal ballistic junctions (TBJs), have been performed. In the first part of the thesis, an overview of the realization and properties of such systems is g

The dynamics of a classical, heavy system coupled to a quantum mechanical light system is studied in a simple time-dependent random matrix model, where the degree of complexity can be changed by a “chaoticity parameter.” It is shown that the energy of the quantum mechanical system diffuses as it interacts with the classical system, providing it is chaotic, while a ballistic behavior appears in the

Measurements of quarkonia isolation in jets at the Large Hadron Collider (LHC) have been shown to disagree with fixed-order non-relativistic quantum chromodynamics (NRQCD) calculations, even at higher orders. Calculations using the fragmenting jet function formalism are able to better describe data but cannot provide full event-level predictions. In this work we provide an alternative model via NR

Electronic transport is studied at low temperatures in two-dimensional electron gases (2DEGs) and in mesoscopic semiconductor microstructures. The method of microwave-detection of the Shubnikov-de Haas effect for the contact-free characterisation of transport properties of 2DEGs is explored using both magnetic-field modulation and light-induced carrier modulation. The methods are compared to magn

Spin crossover (SCO) complexes are highly promising candidates for a myriad of potential applications in room-temperature electronics; however, as it stands, establishing a clear connection between their spin-state switching and transport properties has been far from trivial. In this perspective, an effort to unravel the underlying charge transport mechanism in these SCO complexes, via a general t

We report on a low-temperature magnetoconductance study to characterize the electrical and spin transport properties of n-type InAs nanowires grown by chemical beam epitaxy. A gate-controlled crossover from weak localization to weak antilocalization is observed. The measured magnetoconductance data agrees well with theory for one-dimensional quasi-ballistic systems and yields a spin relaxation len

Mn5Ge3(001) thin films grown on Ge(111) were studied by angle-and spin-resolved photoemission using synchrotron radiation in the 17-40 eV photon energy range. The photoelectron spectra were simulated starting from a first-principles band-structure calculation for the ground state, using the free-electron approximation for the final states, taking into account photohole lifetime effects and k(perpe

High-spin states in Cs-123 were populated in the Ni-64(Ni-64,p4n) reaction at a beam energy of 265 MeV. Gamma-ray coincidences were measured using the Gammasphere spectrometer. Two additional bands have been placed in the level scheme and the four previously known bands have been extended to higher spin. At the highest spins, two of the bands show irregular level sequences. These structures of non

The purpose of this gaper is to analyze and detect changes in body position (BPC) during electrocardiogram (ECG) recording. These changes are often manifested as shifts in the, electrical axis and may be misclassified as ischemic changes during. ambulatory monitoring. We investigate two ECG signal processing methods for detecting BPCs. Different schemes for feature extraction are used (spatial and

This thesis investigates if it is possible to measure the plunger position in a Ledex 282352-023 solenoid actuator without the use of external sensors. To do this, various different methods, all based on comparing the current response to the applied voltage were evaluated from different categories such as calculation time, reliability and distinct position levels. The method that performed best in

X-ray absorption and magnetic circular dichroism spectra of as-deposited and postannealed Fe50 Pt50 /C granular multilayers were measured at both the Fe and Pt L2,3 edges. We demonstrate that the partial L 10 ordering of the FePt nanoparticles induced by thermal annealing results in an increase of the effective spin magnetic moments by 200% at the Fe site and by 65% at the Pt site, while the orbit

Plasma exchange (PLEX) is capable of removing significant amounts of circulating antibodies. In anti-neutrophil cytoplasmic antibody-associated vasculitis, PLEX was reserved for patients with severe presentation forms such as rapidly progressive glomerulonephritis and pulmonary haemorrhage. The Plasma Exchange and Glucocorticoids in Severe ANCA-Associated Vasculitis (PEXIVAS) trial included all co

The state of water in aqueous microemulsion droplets in the system AOT/D2O/isooctane has been investigated by 2H and 17O NMR. Longitudinal relaxation rates are reported as a function of droplet size, droplet volume fraction, temperature, and resonance frequency. We conclude that the surface-induced perturbation of water rotation is of short range (limited to the primary hydration of the AOT head g