Everything we do with electrons depends on their charge, for example the whole of electronics is based around an electron’s negative charge. But electrons have another property, their spin, that could also be used to manipulate them. So a lot of engineers are trying to think up ways we can fiddle with an electron’s spin to do interesting things. The resultant field is called spintronics and it’s exciting cos it opens the possibility of an entirely new form of computing based on spin rather than charge.

But it ain’t just computing that depend son an electron’s charge. Piezoelectric materials also depend on the way charge is distributed within their crystalline structure. When squeezed, this symmetry changes in way that generates a voltage. Conversely, when a voltage is applied, the crystals themselves change shape.

Now Alexy “Koala” Kovalev at Texas A&M University at College and some egghead pals are proposing that electron spin can do a similar thing. Pass a spin-polarized current (one in which all the electron spins point in the same direction) through the right kinda crystal and it will bend or vibrate. That ain’t so useful cos we can make things vibrate pretty good now.

But the converse effect could be very useful. Send a current through an oscillatin’ wire and it’ll spin-polarize it. Koala is calling it the piezo-spintronic effect and it’s handy cos there ain’t that many ways to generate spin-polarized currents right now and none that look as simple as this.

One problem: Koala Kovalev and pals have done some neat thinkin ‘n’ theorizin’ but ain’t built nothin’ yet. The chances are that this kinda piezo-spintronic material ain’t gonna be easy to come by. Time for some metamaterial brainstorming.

Ref: arxiv.org/abs/0711.4430: Nanomechanical Spin-polarizer

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