October 19, 2010

Electricity, Electrons and Educational Institutions

I do so adore alliteration

I've thus far avoided mentioning my college, The Ohio State University, some of that is not to sound overtly favoring them, another part is not always reading their science updates. It is required that you say 'The' by the way, need those definite articles. Otherwise we get confused with Oklahoma State...or something

However, I have now found something interesting, special thanks to people who send me articles by the way

OSU has learned a way to get electricity from a single electron, which will change not only energy efficiency but data processing. Before I get to the nitty-gritty of precisely HOW they do this, I think a physics lesson (or reminder) is in order.

Electrons! The things that orbit the nucleus. Have a negative charge. The flow of them causes electricity (static and otherwise). Electrons have a negative electric charge and, as a result, repel each other. The fact that they repel each other is why we feel things and what makes thing's 'solid'. Atoms are after all 99% empty space, and it's only electron's repulsion of each other that gives atom's substance and connects them with others.
Electrons also have a thing called 'spin' which is precisely what it sounds like, a type of angular momentum found in circular bodies who are affected by forces in an otherwise empty space (much like how the Earth rotates)

So yeah, they're important little subatomic particles.

Now that I've set the stage, researchers at The Ohio State University have showed that there is a way to harness an electron's spin in order to generate a small amount of electricity by making one side of a semi conductor (a material with electrical activity due to electron flow, somewhere between a conductor and an insulator) warmer than another

Why is this important, apart from scientific curiosity? A technology in development uses the spin of an electron to store computer data, the binary ones and zeros, as "spin up" or "spin down." These spin-based electronic, called spintronic, devices generate little heat, which will allow computers to process at faster speeds. Computer data is stored as the presence or absence of an electron charge. The problem is that heat generated in the process limits how fast a computer can process data according to Joseph Heremans, THE Ohio Eminent Scholar in Nanotechnology, and Roberto Myers, THE assistant professor of materials science and electrical engineering at THE Ohio State University (definite articles are fun).

In the experiment, they heated one side of the sample, and then measured the orientations of spins on the hot side and the cool side. On the hot side, the electrons were oriented in the spin-up direction, and on the cool side, they were spin-down. The researchers also discovered, to their own surprise, that two pieces of the material do not need to be physically connected for the effect to propagate from one to the other.

They scraped away a portion of the sample with a file, to create two pieces of material separated by a tiny gap. If the spin effect were caused by electrical conduction (electrons flowing from one part of the material to the other)then the gap would block the effect from spreading. Again, they applied heat to one side. The effect persisted.

They figured that each piece would have its own distribution of spin-up and spin-down electrons. However, one side of the first piece was spin up, and the far side of the second piece was spin down. The effect somehow crossed the gap.

The original spin-Seebeck detection by the Tohoku group baffled all theoreticians at the time. This study confirmed their findings and has opened the door for future technology and even more efficient data processing within computers.
Definite articles baby