Phys.org  February 16, 2023 Electron flow in conductors becomes viscous when electron-electron collisions dominate over collisions with defects and other sources of resistance. An international team of researchers (USA – University of Wisconsin, Japan) investigated such behavior by using scanning tunneling potentiometry to probe the nanometer-scale flow of electron fluids in graphene as they pass through channels defined by smooth and tunable in-plane p-n junction barriers. They observed that as the sample temperature and channel widths were increased, the electron fluid flow underwent a Knudsen-to-Gurzhi transition from the ballistic to the viscous regime characterized by a channel conductance that exceeded […]