movement of viscous fluids. Here, we show that in viscous flows, interactions facilitate
transport, allowing conductance to exceed the fundamental Landauer's ballistic limit G ball.
The effect is particularly striking for the flow through a viscous point contact, a constriction
exhibiting the quantum mechanical ballistic transport at T= 0 but governed by electron
hydrodynamics at elevated temperatures. We develop a theory of the ballistic-to-viscous …