https://www.um.edu.mt/library/oar/handle/123456789/71033 2026-05-02T00:17:28Z https://www.um.edu.mt/library/oar/handle/123456789/92915 Title: Nonlinear optomechanics Abstract: Developed in the 20th century, the branch of physics known as quantum mechanics is the science of studying the behaviour of matter and light on the atomic and sub atomic scale. Optomechanics is the discipline in quantum mechanics which studies the interaction of electromagnetic radiation in the form of photons with mechanical systems through the radiation pressure force. The optomechanical interaction is an intrinsically nonlinear one, and it can therefore cause classical states to develop nonclassical features. In this dissertation we explore the emergence of this nonclassical behaviour as a function of the system parameters. Many mathematical properties may be used to determine whether a state is in fact displaying classical or non-classical behaviour. Non-classicality may be generated for the light, mechanical or the light and mechanical field simultaneously. The properties of the Wigner quasi-probability distribution function were made use of throughout this dissertation in order to pinpoint any hints of non-classicality, specifically the negativity of the Wigner function. Interesting results were the analysis of the degree of non classicality and the analysis of the maximum negativities of the Wigner functions under specific conditions. Description: B.SC.(HONS)MATHS&PHYSICS 2018-01-01T00:00:00Z https://www.um.edu.mt/library/oar/handle/123456789/92483 Title: Charging a quantum battery : investigation of the quantum advantage provided by entanglement Abstract: A quantum system can be used to store energy in its energy levels, thereby a.ding as a battery. The main aim of this dissertation is to investigate the effect of quantum entanglement on the power generated during the charging of a quantum system for three different cases: closed, open and approximated classical systems. The first case illustrates the advantage provided by quantum entanglement, where the time evolution decreases by a factor of 1/N for N qubits and hence the power produced increases by the same factor. In the other two cases, the degree of entanglement and consequently the amount of power generated was reduced. This work shows that entanglement provides a quantum advantage in power generation over its classical counterparts. Description: B.SC.(HONS)PHYSICS 2018-01-01T00:00:00Z https://www.um.edu.mt/library/oar/handle/123456789/91762 Title: A quantum perspective on random walks on graphs Abstract: The term 'quantum random walk' was coined by Aharonov, Davidovich and Zagury in 1993, when they showed that the average path length of a quantum random walk may be larger than that of a classical random walk due to quantum interference effects. Random walks are prevalent in the design of algorithms and the use of quantum random walks over their classical counterpart may provide an advantage when it comes to solving certain problems. Also, the introduction of small amounts of decoherence has been shown to improve the uniformity in the spreading of the walk in some cases, without necessarily losing all quantum features. This project will consider the discrete model of the quantum random walk generalised to certain types of graphs, and will look into the effect of different rates of decoherence on this type of walk. Description: B.SC.(HONS)MATHS&PHYSICS 2018-01-01T00:00:00Z https://www.um.edu.mt/library/oar/handle/123456789/91404 Title: Assessing the night-sky brightness of the Maltese islands Abstract: Artificial lighting is meant to provide good visibility during the night. Bad practices in illumination, however, have led to excess light being emitted into the atmosphere, causing artificial sky-glow. Despite the ever increasing agreement among scientists that light pollution has adverse effects on ecology and even human health (besides an obvious impact on astronomical observations), oftentimes authorities are still not proactive in considering light pollution as a serious issue that merits urgent mitigation. This project has involved the quantification of night-sky brightness levels, by taking in-situ measurements all over Malta, Gozo Comino. It presents a detailed ground-based night sky brightness map for the Maltese Islands - the first of its kind. This map reveals that the night-sky brightness over the Maltese Archipelago is remarkably high, and the Milky Way should be visible in less than 13% of the country. Description: B.SC.(HONS)MATHS&PHYSICS 2018-01-01T00:00:00Z