In quantum information theory, the presence of Bell non-local correlations is a key indicator of non-classical behavior in multipartite quantum systems. However, non-locality is not exclusive to...Show moreIn quantum information theory, the presence of Bell non-local correlations is a key indicator of non-classical behavior in multipartite quantum systems. However, non-locality is not exclusive to quantum mechanics; more general theories with stronger non-local correlations than those achievable within the quantum formalism can be constructed. While distinguishing classical (local) correlations from non-local correlations can, in principle, be accomplished by a finite number of linear constraints called Bell inequalities, distinguishing between quantum and post-quantum correlations requires solving a hierarchy of SDP relaxations. To simplify the certification of quantum correlations, a whole line of research has focused on searching for an operational principle that can explain the limited strength of quantum correlations. Among the proposed principles, information causality (IC) stands out as the most promising, though deriving general correlation bounds from it is also very complex. We review the various attempts to formalise IC and their effectiveness in constraining bipartite non-locality, as well as the challenges encountered in studying this principle. In particular, we perform numerical experiments to showcase the insufficiency of all the currently proposed IC bounds to capture the full potential of the principle for correlations near the quantum boundary. Furthermore, we demonstrate the instability of two out of three bounds under non-locality distillation.Show less
This thesis is concerned with the design of numerical methods for solving the Schrödinger equation for a system of two-electrons in a double quantum dot. Theoretical background is presented for the...Show moreThis thesis is concerned with the design of numerical methods for solving the Schrödinger equation for a system of two-electrons in a double quantum dot. Theoretical background is presented for the physics of a two-electron quantum dot. Implementation of the double dot system is via the QuTiP library is discussed and a numerical approach for the treatment of the system using the density matrix formalism is presentedShow less
Spectropolarimetry is a versatile technique that allows an observer to measure both the spectrum of an object and the polarization of each point on that spectrum. Spectropolarimeters, like other...Show moreSpectropolarimetry is a versatile technique that allows an observer to measure both the spectrum of an object and the polarization of each point on that spectrum. Spectropolarimeters, like other spectrographs, generally use a slit to restrict their field of view to a line. However, slits have a long history of polarizing the light they transmit. Although multiple theories exist, and the polarizing behavior of slits near wavelength-scale is experimentally well-tested, the polarizing behavior of the generally wider spectrographic slits is less well-known and well-tested. We present a first step towards a new general model of the polarizing effects of slits based on waveguide theory and the eigenmode expansion that already shows the general expected behavior; linear polarization perpendicular to the slit’s long axis, as well as retardation effects with a similar perpendicular fast axis. Additionally, we tried to experimentally test the model’s predictions, but our setup proved insufficient. This was due to systematic errors, which could be removed using a different method, for which we provide suggestions.Show less
