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Researchers Spin Out Smaller Electronics Than Ever
schliz writes "Scientists have found a more efficient way to harness the spin of an electron to store and process information. The new technology, dubbed 'spintronics', has potentials in the development of nanoscale devices that are much more energy efficient than current charge-based electronic devices. Researchers expect the new technology to be incorporated in computing circuitry within the next decade."
Even better, a clean article-only, non-advertising version of the article here: http://www.computerworld.com.au/index.php/id;86278 6408;fp;;fpid;;pf;1
Horns are really just a broken halo.
So, besides being wrong or misleading in other areas, the article is actually right about the electron not physically moving in order to change it's spin orientation. As has been pointed out, it does require energy, however. Supposedly this is less than the typically required voltage change.
*see references at bottom of page spintronics
Chaos maximizes locally around me.
But it's not about rotating an electron at all. We're talking about spin angular momentum, which is a quantum mechanical property of particles like electrons and cannot really be related back to any sort of classical quantity. The only reason we call it 'spin' is because it's what gives the electron angular momentum. As far as we (physicists) know, electrons lack any sort of high-level structure, so it doesn't even make sense to talk about rotating them.
The idea is that instead of moving charges around, it would be much more efficient to harness intrinsic properties of 'stationary' particles -- spin up and spin down, instead of plus and minus charges. If we can figure out some way to easily flip the spin on an electron, then it could conceivably be used as a bit to store information.
Legalize it.
But, spin is far more and far more important than just the Stern-Gerlach effect. Above all, spin is angular momentum, just as any rotating object has angular momentum (hence the name spin). Now, we know that even if electrons and other (we think) fundamental particles have some kind of non-infinitesimal structure (in which case they are quite likely not fundamental), that structure is so small that in order to produce the measured angular momentum, the outermost portions of the electron would have to be moving faster than the speed of light. So, unless we've gotten something wrong, you are correct that the electron is not really spinning. But nonetheless, spin is angular momentum, a locally conserved quantity.
Spin also plays a very important role in both chemistry and nuclear physics (in similar ways). The spin of a particle determines whether it is a fermion or a boson, and thus how it plays with other particles like itself. You can't have more than one electron in any given quantum state, because the electron is a fermion. Since spin is part of the quantum state, you can have two electrons in one energy state, so long as they have opposite spins. If spin didn't exist, chemistry would be considerably different. Nuclear physics is a little bit like chemistry of the nuclei (protons and neutrons instead of electrons), and without spin, which elements are stable or not would be quite different.
Finally (not the last that spin is important for, just the last I'm going to talk about), spin is important in solid state physics, and thus in everyday life. That chair you're sitting in? Wouldn't be solid if it weren't for spin. Because electrons are fermions, and can't be in the same state as other electrons, solids don't collapse. Collapsing would require moving electrons down to a lower energy state, and at some point, all lower states are filled. So there is an outward pressure due to the fact that electrons are fermions. The difference between fermions and bosons? Spin. If there were no spin, everything would have to be a boson (or all distinguishable particles), and we wouldn't really get any solids. </gross oversimplifications>
SIGSEGV caught, terminating
wait... not that kind of sig.