What physics controls the properties of quantum matter, such as how electrons flow inside high-temperature superconductors? This question has captivated the physics community and industry for... Show moreWhat physics controls the properties of quantum matter, such as how electrons flow inside high-temperature superconductors? This question has captivated the physics community and industry for decades, in part due to the great technological potential such materials have, but also because they have resisted all traditional methods of understanding. It calls for a complete change in paradigm. An unexpected venue for progress was found in the study of gravity. By studying special gravitational solutions such as black holes and stars made of electrons, it turns out to be possible to shed some light on the physics and transport properties of quantum matter. This analysis relies on the use of high-performance computations to obtain these gravitational solutions, but the payoff is access to uncharted areas of physics. So far, such methods have successfully brought some insight into the flow of energy in such systems, but the flow of electric charge or the quantum information patterns remain shrouded in mystery. The findings of this thesis address key parts of these questions, particularly in the context of black holes as models of exotic quantum metals. Show less