  In this PhD thesis, several aspects regarding maximal entanglement are
analyzed. In the first chapter, Bell Inequalities are analyzed from an
operational perspective as well as novel Bell inequalities are obtained
together with their optimal settings for a maximal violation. Multipartite
figures of merit, in particular, the hyperdeterminant, are the subject of the
second chapter. They are applied to detect quantum phase transitions in several
spin models. The third chapter focuses on the simulation of the XY model in a
quantum computer. The quantum circuit obtained is tested in three current
quantum devices. Quantum computers must be able to generate and hold highly
entangled states in order to show a quantum advantage. This statement is
analyzed in chapter four, where quantum circuits for maximally entangled states
are presented. Finally, chapter five analyzes how maximal entanglement is
generated at its fundamental level. Maximal entanglement constraints the QED
vertex interaction and predicts a value for the weak mixing angle close to the
experimental value.
