Interconnects, the wires that string transistors together into circuits on microchips, have long been built from copper due to its high conductivity. However, as electronics continue to shrink, copper becomes a dramatically worse conductor. Now scientists find that a new class of materials containing exotic quasiparticles might one day help enable next-generation interconnects that become better conductors the thinner they get.The problem that copper interconnects now face has to do with the mean free path of the metal, the average distance an electron can travel before it runs into a molecule. Once copper wires shrink beneath this limit—in copper’s case, 40 nanometers—their electrical conductivity drops dramatically because their electrons start experiencing more collisions.Researchers ar
