NONTECHNICAL SUMMARY One of the most exciting discoveries of the last century is quantum entanglement, a phenomenon in which distant quantum particles, such as ordinary electrons in a material, exhibit correlations (become affected by the existence and behavior of the others) that defy our everyday intuition that objects carry their own pre-existing properties. Quantum entanglement is at the heart of technologies such as quantum computing, and is also crucial to several unusual properties of materials at low temperatures. However, entanglement is typically fragile, i.e., easily disrupted by interactions with a quantum system's environment. One of the key questions, therefore, concerns the phenomena occurring precisely at the boundary where quantum entanglement is lost, giving way to intuition familiar in everyday life. Such "phase transitions" remain poorly understood, especially in systems composed of a macroscopic number of interacting electrons. This project will focus on such transitions in a variety of contexts, ranging from materials where electrons are strongly entangled with each other, to "quantum hard drives", systems which can serve as storage space for information exploiting entanglement. The PI will utilize a combination of analytical tools and state-of-the-art numerical simulations to explore the research. Graduate students supported by this proposal will actively lead and carry out a substantial portion of the described research. To broaden societal enga