Phys.org   July 20, 2022 An international team of researchers (USA – Columbia University, Cornell University, Brown University, Singapore, Japan) combined theoretical and experimental study of ambipolar hydrodynamic transport in bilayer graphene to demonstrate that the conductivity is given by the sum of two Drude-like terms that describe relative motion between electrons and holes, and the collective motion of the electron-hole plasma. As predicted, the measured conductivity of gapless, charge-neutral bilayer graphene was sample- and temperature-independent over a wide range. Away from neutrality, the electron-hole conductivity collapsed to a single curve, and a set of just four fitting parameters provided quantitative […]