I have got some mega news for you, my friends, and it involves two of our favorite words:
graphene and superconductors.
Let’s just dive right in, shall we?
To understand this latest news, we have to go back to last year.
The physics world was sent into a tizzy by the discovery of a ‘magic angle’ in graphene.
Now, graphene is a single-atom thick layer of carbon that forms a hexagonal lattice pattern,
and its atomic arrangement gives it certain exciting properties, like being over 200 times
stronger than steel, flexible, transparent, and highly conductive.
This last property was highlighted in 2018 when researchers put two layers of graphene
on top of each other, and twisted them at exactly 1.1 degrees.
They cooled the graphene structure to just above absolute zero, applied a strong electric
field, and found that not only are these graphene bilayers highly conductive, they exhibit
alternating areas of conductivity and insulation.
So in some areas, they saw graphene bilayers with a twist to behave like a superconductor.
That means there’s no resistance to an electrical current and therefore, the current can flow
super efficiently.
But here’s the kicker: we don’t know why!
We don’t fully understand what’s happening at the molecular level to make this particular
orientation of graphene capable of superconduction And this year, in further exploring the capabilities
of this seemingly ‘magical’ twist, scientists have now discovered something that is arguably
an even bigger deal.
An international team at the Institute of Photonic Science in Barcelona ‘cleaned up’
the experiment.
They made what they call ‘magic-angle twisted bilayer graphene devices’, a name that will
never get old for me.
Essentially, they took these two stacks of graphene rotated at the magic angle, and used
a mechanical squeezing process to eliminate impurities.
This squeaky clean version of the experiment allowed them to see details they hadn’t
before like the device’s incredible versatility.
It turns out, graphene stacked and turned at the magic angle can be tuned to act as
many things.
Depending on the charge running through it, the experimental setup could act as an insulator,
a superconductor, or even a magnet!
And j
ust by changing the current running through the device, scientists could turn
states on and off, which is exciting for many reasons.
It could make these materials really useful inside electronics, as they're controllable
in much the same way our current electronics are: they’re tunable.
But this new research is also a step toward solving the mystery of exactly how this happens.
Work like this lets us explore and manipulate the microscopic world inside graphene devices,
allowing us to better understand how this material works and how we can use it.
In addition to furthering our existing understanding of how these bilayer graphene stacks behave,
the team was able to beat the record temperature at which the material behaves as a superconductor.
And this is incredibly important, as our existing ways of inducing superconducting behavior
in most materials requires extremely low temperatures and/or high pressures.
Superconductors would be so useful if they didn’t require such low temperatures to
function.
And in the field of physics, discovering or creating a room-temperature superconductor is considered
something of a holy grail.
This most recent graphene work has demonstrated that graphene magic angle bilayer devices
can act as superconductors at a temperature above 3 Kelvin—which, while not the warmest,
is the highest temperature ever demonstrated for a graphene superconductor.
Along with graphene’s other tantalizing properties, achieving superconductivity at
easier-to-maintain temperatures could be seriously useful in many future applications.
Things like incredibly efficient power transfer, hovertrains, or even quantum computing.
But that future can only really become a reality if we develop a better understanding of the mechanisms
of action at play, and can use that understanding to improve the performance of ‘magic’ materials like this.
What are your thoughts on graphene and its many ‘magical’ properties?
Let us know down in the comments below, and for more on superconductor breakthroughs,
check out this video over here.
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thanks so much for watching. I'll see you next time.