Lithium is the lightest solid metal, it’s soft, silvery-white, with a low melting point and reactive. Many of its physical and chemical properties are more similar to those of the alkaline earth metals than to those of its own group. This light alkali metal has intrigued scientists for two decades with its remarkable diversity of physical states at high pressures. Now scientists have predicted fascinating new properties of lithium.
Using cutting-edge theoretical calculations performed at NERSC, scientists have shown that when you put a lithium crystal under pressure, the atomic structure changes and, somewhat counterintuitively, its conductivity drops, becoming less metallic. In addition, it becomes topological, with electronic properties similar to graphene.
Scientists noted, “Topological materials are a recently discovered class of solids that display exotic properties, such as having insulating interiors yet highly conductive surfaces, even when deformed. They are exciting for potential applications in next-generation electronics and quantum information science.”
“Lithium becomes topological at high but experimentally achievable pressures, comparable to one-quarter of the pressure at the Earth‘s center.”
Stephanie Mack, a graduate student research assistant at Berkeley Lab and first author of the study said, “Thus far, most experimentally verified topological materials contain heavy, potentially toxic, elements. But we’ve predicted that lithium, ostensibly a simple metal, can also have these unique properties.”
The study is published in PNAS.