Electronics work by shuffling electrons through circuits and logic gates to perform calculations,
but in doing so they have to overcome resistance, which wastes energy and generates heat.
So instead of forcing electrons to push each other along, what if
we just made them do the wave?
Electrons have a negative charge; it’s a fundamental part of what they are.
They also have a property called spin, and this spin can be oriented either up or down.
If the spins of the outermost electrons in an atom are aligned the same direction,
they’ll generate a magnetic field, making the atom a tiny magnet.
If all the atoms in a material have their magnetic fields aligned the same way,
the material will act as a magnet.
(I could make the Insane Clown Posse joke, but I won’t. I'm not going to do it.
It’s 2018 and we’re officially laying the magnets joke to rest.)
Anyway, it’s possible to reverse the direction of the magnetic field of an atom in a material
by applying energy.
When that happens, the strength of the magnetic field in that area drops a bit;
it's effectively the same as a partial reversal of all the tiny magnets in that group.
This partial reversal spreads, like a crowd doing the wave at a stadium, passing the energy
that dampened the magnetic field along.
This wave of energy can also be thought of as a particle, called a magnon.
Just like electrons in a circuit, a magnon can be used to carry information, with some
advantages over moving electrons, like using less energy and generating less heat
(which is good, because sometimes I worry about what my laptop is doing to me
when it’s atop my lap.)
But while the silicon circuits that conduct electrons are relatively easy to make,
the magnets that transport magnons are not.
One reason we’re still using electronics instead of magnonics is because the media
that carry magnons well are notoriously hard to make and harder to combine with other materials.
Currently most magnonic researchers use a material called yttrium iron garnet -- or
YIG -- to carry the waves.
A film of high quality YIG has to be grown on a matching lattice structure like gadolinium
gallium garnet. Hard to say, harder to combine with other substrates, like silicon.
So researchers started exploring elsewhere, and came across a material first made in 1991.
This material, called vanadium tetracyanoethylene, was the first carbon based magnet that was
stable at room temperature.
Well so long as it wasn’t exposed to oxygen, in which case it can burst into flame.
But aside from the surprise fire, it’s great for studying magnonics, keeping the magnons
just as stable as YIG while they persisted for record-breaking times.
If researchers can make a practical material for magnons to travel through, then the next
step is making digital logic gates like the transistors in a chip.
Fortunately researchers don’t have to figure out entirely new transistors that can respond
to magnons.
It’s possible to convert a magnon into an electrical signal thanks to something called
the inverse spin Hall effect, and then it’s just a matter of sending electrons through
the transistor like we’ve always done.
This means researchers could combine magnonics and electronics, bringing them one step closer
to smaller, faster, more efficient computers.
For now though researchers are exploring other materials that might work even better than
vanadium tetracyanoethylene.
Hopefully they find one that doesn’t catch fire when you crack a window.
Dive deeper into the future of computing and watch this video here, where I explain how
using photons in computers instead of electrons could make light-speed computing possible.
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