New method proposed to study the hydrodynamic behavior of electrons in graphene

By studying how the electrons contained in two-dimensional graphene can literally behave like a liquid, researchers have opened the way to new research on a material that could allow future electronic computing devices to go beyond silicon transistors.

Research on a new method for more accurate demonstration of graphene's electronic behavior in graphene has been developed by Ravishankar Sundararaman, researcher at Rensselaer, and a team at Quazar Technologies (India) led by Mani Chandra. Physical examination B.

Graphene is a unique atomic layer of graphite that has attracted a lot of attention because of its unique electronic properties. Sundararaman recently said that scientists have proposed that, under good conditions, graphene electrons can flow like a liquid in a way that is unlike any other material.

To illustrate this, Sundararaman compares electrons to drops of water. When a few droplets line the bottom of a jar, their movement is predictable as they follow the movement of the container when it is tilted from one side to the other. This is how electrons behave in most materials when they come into contact with atoms and bounce off. This leads to the Ohm law, the observation that the electric current flowing in a material is proportional to the voltage applied across it. Remove the voltage and the current stops.

Now imagine a glass half full of water. The movement of the liquid, especially when you shake the pot, is much less uniform, as the water molecules usually come in contact with each other instead of the pot walls, allowing the water to move. water to move and swirl. Even when you stop moving the glass, the movement of the water continues. Sundararaman compares this to the way electrons continue to flow in graphene, even after the voltage has stopped.

Researchers knew that the electrons present in graphene could do this, but it is difficult to conduct experiments to create the conditions necessary for this behavior. Previously, scientists applied stress to a material and searched for negative resistance, but the methods used were not very sensitive.

The calculations presented by Sundararaman and his team in this last work show that by oscillating the tension (imitating the shaking movement in the example of the jar), the researchers can identify and measure more precisely the vortices created and the hydrodynamic behavior. electrons.

"You can get really strange and useful electronic properties," said Sundararaman, an assistant professor of materials science and engineering. "Because it flows like a liquid, it has the potential to keep its momentum and keep going.You could have a conduction with a lot less energy loss, which is extremely useful for making devices to low energy consumption very quickly. "

Sundararaman explained that it was necessary to do a lot of research before creating a device of this type and apply it to the electronics. But the method outlined in this article, including the measurements that, according to the researchers, should be taken, will allow a more accurate observation of this hydrodynamic flow of electrons in graphene and other promising materials.