Spin It; Spin It Good

It takes trillions of electrons in order to see them. An electron is one of the smallest particles known to man. It has no structure. It's like a one-dimensional point. So how can it spin?

There are plenty of things in this world that I just can’t wrap my brain around no matter how much I read about the subject. It just baffles me. Quantum mechanics is one of those things.

Take, for example, the electron. It is a fundamental particle, meaning that as far as we know, there are no smaller internal structures. Unlike the proton and neutron, which are made up of quarks and gluons, there is nothing smaller inside of an electron.

Now, an electron has several fundamental properties, one of which is it’s “spin.” Why do they call it spin? I have absolutely no idea. As far as I can tell from reading up on the subject, the electron has no structure – remember it’s made of nothing – so it can’t be a sphere. To me, this indicates that it can’t be spinning in the classical sense.

What I mean to say is that it can’t be rotating about an axis like the Earth, because it doesn’t have an axis on which to rotate.

As far as I can tell, the idea is best expressed when you think of an electron as a wave instead of a particle. Yes, just like the photon (light), an electron can be considered as a wave. And this wave has a unique structure that comes in one of two forms.

Picture a wave on a graph; it has crests, troughs, an amplitude, etc. An electron’s “spin” relates to whether that graph is shifted a little bit to the left or a little bit to the right. But for some reason, the two types are called “up” and “down.”

A wave graph for your benefit. Every electron is identical to every other electron, except that their wave functions are shifted in one of two ways creating an "up" and "down" spin number.

Lucky for us, there are a lot of really smart people in world, some of which who actually know what an electron’s spin means. And also luckily for us, some of them are at Ohio State discovering how to use this fundamental quantum property to create computer chips that run off of their own heat.

Spintronics” is a new field that has only been established within the past few years. The idea is to control an electron’s spin and use it to store information on a computer chip. Instead of electrical points being on or off to store the binary code, an electron would be either up or down.

This is possible because an electron acts like a magnet, which is something that I do understand. This means it has exhibits both a positive side and a negative side, with its orientation depending on whether its spin is up or down. But unlike magnets, these spin characteristics seem to be affected by heat (whereas typical magnets are affected only by electricity and magnetism, which are really the same things, but that’s another one I don’t completely understand.)

This phenomenon was discovered only a couple of years ago in metals by some really smart scientists in Japan. Building off of their research – because that’s what science does – the Ohio State researchers Joseph Heremans, Ohio Eminent Scholar in Nanotechnology; and Roberto Myers, assistant professor of materials science and electrical engineering; tested this so-called “spin-Seebeck” effect in a semiconductor, which is what computer chips are made from.

One such semiconductor is gallium arsenide. The researchers added manganese to give the new material – gallium manganese arsenide (GaMnAs) – magnetic properties.

Back in Japan, the researchers discovered that when one side of a long piece of metal is heated and the other is cooled, the electrons on the hot side are up while those on the cool side of the pillow are down. These results baffled the scientists then, and I’m pretty sure they still do to this day.

But nonetheless, Ohio State took the experiment to GeMnAS and got the exact same results in a paper published in Nature Materials. Even more surprisingly, they found that the effect lingered even when the piece of material was split into two pieces.

What this means is that scientists have taken the first steps towards using heat to control the spin states of electrons in a material used for computer chips. Actually controlling individual electrons in a precise and predictable manner in order to use them to store information is a long ways off. But when we get there, it’s possible that these new spintronics could use the heat generated by traditional computer chips to operate. This means not only denser electronics with more storage capacity and faster computations, but no energy losses through heat and a much more efficient machine.

Now if only I understood what the hell they were talking about.


About bigkingken

A science writer dedicated to proving that the Big Ten - or the Committee on Institutional Cooperation, if you will - is more than athletics.
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