When twisted into ‘magic angle’, graphene becomes a superconductor

6 Mar 2018

Image: OliveTree/Shutterstock

By twisting a sandwich of graphene at a particular angle, it develops a powerful and peculiar superconductor ability unlike any other material.

Materials that act as superconductors – whereby they experience no electrical resistance – would appear to offer enormous potential, but they unfortunately have a massive drawback.

So far, any superconductors have only existed when contained at temperatures close to absolute zero. When it comes to ‘high-temperature’ superconductors, they can only work at the ‘sweltering’ temperature of -140C.

However, new research conducted by an international research team has found that the so-called ‘wonder’ material graphene could be the answer to one day creating a functional, room-temperature superconductor.

According to Nature, the team of physicists found that by creating a sandwich of two graphene layers, each just an atom thick, and twisting it at the ‘magic angle’ of 1.1 degrees, it shows superconductive properties.

While these initial tests were conducted at temperatures of just 1.7C above absolute zero, the results suggest that it can conduct electricity at high-temperature superconductor conditions.

On top of that, graphene has superconductive properties, with just one-10,000th the electron density of a normal superconductor.

If such room-temperature superconductivity was achieved, it could revolutionise many aspects of society, from an overhaul of public transportation, to how we generate and use energy in our homes.

A frenzy of experiments to follow

One of those involved in the research, Robert Laughlin of Stanford University, has said that, if confirmed and expanded upon elsewhere, the new findings could have major implications.

“We can expect a frenzy of experimental activity over the next few months to fill in the missing parts of the picture,” he said.

The actual discovery of the bendy, superconductive properties was almost by accident, as the researchers were just trying to see how graphene would react when placed at the angle of 1.1 degrees, which has been dubbed by some as the ‘magic angle’, based on theoretical models.

Predictions had shown that offsetting the atoms between layers of graphene at this angle could induce the electrons in the sheets to act in strange ways.

At this stage, graphene’s strangeness has been well documented. Recent findings from another research team noted that the material’s mysterious ability to act as a catalyst in fuel cells was actually down to hidden metallic contamination in the lattice.

The latest research has been published in two separate papers, and you can read more here.

Colm Gorey was a senior journalist with Silicon Republic