Observation of the Gurzhi Effect in Ultra-high Mobility Corbino Rings

In 1963, based on theoretical considerations, Gurzhi predicted that a decrease in resistance with increasing temperature should be observable when a clean conductor is confined to a constricted geometry. This effect, now known as the “Gurzhi effect” [1,2] is the result of hydrodynamic effects occurring in a highly interacting system with low disorder. In this talk, I will show our observation of the Gurzhi effect (below 1K) in an annular ring formed in an ultra-high mobility GaAs/AlGaAs two-dimensional electron gas system (2DEG). A four-terminal Corbino geometry was used since it only probes the bulk properties of the 2DEG, hence eliminating any potential spurious effects due to edges and/or geometry of the sample. The effect observed is fully consistent with recent calculations of various lengthscales by Anh and Das Sarma [3], and it provides a direct observation of hydrodynamic effects in the transport properties of an ultra-high electron mobility system.