Electrons flowing like liquid in graphene start a new wave of physics

A new understanding of the physics of conductive materials has been uncovered by scientists observing the unusual movement of electrons in graphene.

Graphene is many times more conductive than copper thanks, in part, to its two-dimensional structure. In most metals, conductivity is limited by crystal imperfections which cause electrons to frequently scatter like billiard balls when they move through the material.

Now, observations in experiments at the National Graphene Institute have provided essential understanding as to the peculiarbehaviour of electron flows in graphene, which need to be considered in the design of future Nano-electronic circuits.

In some high-quality materials, like graphene, electrons can travel micron distances without scattering, improving the conductivity by orders of magnitude. This so-called ballisticregime, imposes the maximum possible conductance for any normal metal, which is defined by the Landauer-Buttiker formalism.

Appearing today in Nature Physics, researchers at The University of Manchester, in collaboration with theoretical physicists led by Professor Marco Polini and Professor Leonid Levitov, show that Landauer's fundamental limit can be breached in graphene. Even more fascinating is the mechanism responsible for this.

Last year, a new field in solid-state physics termed 'electron hydrodynamics' generated huge scientific interest. Three different experiments, including one performed by The University of Manchester, demonstrated that at certain temperatures, electrons collide with each other so frequently they start to flow collectively like a viscous fluid.