Behold the future: Superconductive graphene

18 Feb 2016

Graphene, widely accepted as a wonder material perfectly positioned to revolutionise technology once we get around to working it all out, has just acquired its first superpower.

Japanese researchers have created what they call ‘superconductive graphene’, which allows for the immensely fast transport of electricity, placing another flag on a field of landmarks that’s growing rapidly.

A team from Tohoku University and the University of Tokyo has developed a way of growing “high-quality” graphene on a silicon carbide crystal (SiC), all by mastering the number of sheets needed.

What’s high quality? Well, electrons in graphene are pretty cool. They form a special state called Dirac-cone, behaving as if they have no mass and, therefore, acting very quickly.

In essence, that means graphene has a very high level of electrical conductivity, offering very little resistance. Very little, yet still some.

A bit cold

However, its superconductive properties have now been discovered, although it’s only achievable at -269oC, which is important for obvious reasons, namely that it’s wildly impractical at the moment.

As part of the researchers’ investigation, the idea of controlling the number of graphene sheets resulted in bilayer graphene, within which the researchers inserted calcium atoms (Ca).

superconductivity

This is the crystal structure of Ca-intercalated bilayer graphene fabricated on SiC substrate, via Takashi Takahashi

They checked the electrical conductivity and noticed the lower the temperature the weaker the resistance, specifically when you reach -269oC.

Strangely, neither the genuine bilayer nor lithium-intercalated bilayer shows superconductivity per se, and it’s likely the superconductivity is coming from the electron transfer from Ca atoms to graphene sheets.

superconductivity

The temperature dependence of electrical resistivity of Ca-intercalated bilayer graphene, measured by the micro four-point-probe method. The resistivity shows a rapid decrease at around 4 K and reaches “zero” at 2 K, showing the emergence of superconductivity, via Takashi Takahashi

Ever stronger

So, that’s superconductivity added to a growing portfolio of graphene’s amazing characteristics. For example, late last year, researchers discovered that if you stretch out the wonder material it creates a “powerful, adjustable and sustainable magnetic force”.

You can use it to manipulate and programme sheets to walk and you can produce the wonder substance for a fraction of the cost it used to be.

How? Well, watch this.

Electricity image via Shutterstock

Gordon Hunt was a journalist with Silicon Republic

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