Superconductor junctions blur the line between two quantum effects

Researchers have measured the full differential conductance matrix, defined as Gij = ∂ Ii/∂ Vj, moving beyond standard linear response measurements in three-terminal normal-superconductor-normal devices. These devices are based on topological insulator nanowires, and the work reveals how crossed Andreev reflection and elastic co-tunneling, two competing quantum processes, respond to applied voltages. Specifically, the team observed that crossed Andreev reflection is enhanced when V1 = V2, while elastic co-tunneling is enhanced when V1 = -V2, offering a potential pathway to control these subtle quantum effects. Researchers at…