Researchers at Imperial College London claim to have developed technology that would enable the creation of three-dimensional microchips, which will dramatically increase their memory capacity. According to their press release:
"by using nanotechnology it is possible to reproduce the key functions of semiconductor electronics in microchips using only the 'spin' of electrons, which is responsible for magnetism, rather than the more conventional 'charge' that traditional microchips use."
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Member since:2005-07-06
'Spin' is called what it is for a particular reason. While spin is an intrinsic property of electroncs (which can't 'spin' in the classic sense, because they are point masses), it leads to certain phenomena that a real spinning charged object would exhibit, such as a magnetic moment. To quote Wikipedia:
Particles with spin possess a magnetic moment, just like a rotating electrically charged body in classical physics. However, this magnetic moment exists even for point particles like the electron, and for electrically neutral particles like the neutron. This magnetic moment can be experimentally observed, by the deflection of particles by inhomogenous magnetic fields (as in the Stern-Gerlach experiment) or by the magnetic fields generated by the particles themselves. In fact, ferromagnetism arises from the alignment of the spins of the atoms in a solid.
To be fair, the latter information can't be found in most high-school textbooks, and is usually the subject of an introductory materials science course.
Member since:2005-08-28
Member since:2005-07-06
From a text on spin and magnetic moment of electrons:
The term "electron spin" is not to be taken literally in the classical sense as a description of the origin of the magnetic moment described above. To be sure, a spinning sphere of charge can produce a magnetic moment, but the magnitude of the magnetic moment obtained above cannot be reasonably modeled by considering the electron as a spinning sphere. High energy scattering from electrons shows no "size" of the electron down to a resolution of about 10-3 fermis, and at that size a preposterously high spin rate of some 1032 radian/s would be required to match the observed angular momentum.
The rest gets rather complicated. That ferromagnetism is due to electron magnetic moment is a hotly debated topic, given that electron magnetic moment has an unexplained "fudge factor" g in the equation. That and the fact that magnetic domains are on the order of 300 atoms of iron has led to newer explanations that don't use electron spin. It makes for fun reading. 
Member since:
2005-07-06
I know it's "dumbed down" for the readers, but I sincerely hope the physicist they talked to didn't actually say spin is responsible for magnetism. Going back to your old days of physics and chemistry, electrons exist in shells around the nucleus. By the Pauli Exclusion Principle, fermions with the same characteristics cannot exist in the same place at the same time. So how do you get multiple electrons into the same shell? One property is different, and we call that property "spin." It has NOTHING AT ALL to do with an electron spinning!
Metals share electrons in their outer shell. This sharing of electrons is what gives them their characteristics, like conductivity. Atoms tend to clump together into larger structures. Different atoms clump in different ways. Depending on the atom (and things like impurities), these larger structures of metallic atoms share their outer shells in a manner that electrons moving around the larger structure all constitute a charge in motion, creating a magnetic field. If enough of these macro structures are oriented in the same direction, you can actually measure the magnetism and use it for things like holding papers to your refrigerator.