Phase Boundaries, Isotope Effect and Superconductivity of Lithium Under Pressure

Lithium, the simplest element with core electrons, serves as a model system for understanding dense sp-band metals and quantum phenomena such as electron localization and topological phases. Under extreme pressures, it undergoes intricate structural transitions that challenge conventional theories, while its low atomic mass enhances quantum nuclear effects. Here, I present the experimental studies of structural properties of lithium under pressure in several pressure and temperature ranges. In particular I will present the results of the structural phase boundaries of lithium isotopes within their superconducting range and provide an explanation for the pressure dependence superconducting behavior of lithium isotopes. I will also present our recent results on the structural properties of warm dense lithium.