Atoms are the fundamental building blocks in chemistry. An atom is composed of a positively charged core called the nucleus (consisting of protons and neutrons), surrounded by a cloud of negatively charged particle(s) called the electrons. The electrons are the prime movers in electricity (where the negatively charged particles travel from the negative to the positive electrode, thus transferring energy), and in electronics (where the flow of electrons or other electrically charged particles is controlled in devices such as semiconductors).

Electron Spin (Courtesy: Prentice-Hall)The electric charge is a fundamental property of particles such as protons or electrons, and is the driver of Electromagnetism. All of our electrical and electronic devices operate on the electrical charge. However, a new concept based on the spin of an electron, is all set to revolutionize the industry.
The spin is a fundamental property associated with sub-atomic particles. Essentially, it is a fixed angular momentum (similar to rotation in our everyday world, but there is no equivalent in sub-atomic physics) intrinsic to the particle. An electron can have a spin of ±h/4∏ (where h is the Planck's constant, and ∏ = 3.1415...). Since an electron can have only two (up or down) spin values, the spin can be used as the basis of a binary system, where say, '0' = up spin, and '1' = down spin.
However, unlike the electric charge, it is very hard to control or manipulate the spin of an electron. This has hampered the development of any device based on the spin of the electron, until now. Physicists in Europe, California and at Ohio University now have found a way to manipulate the spin of an electron with a jolt of voltage from a battery, according to research findings published in the recent issue of the journal Physical Review Letters:):).
In this study, scientists applied voltage to the electron in a quantum dot, which is a tiny, nanometer-sized semiconductor. The burst of power changed the direction of the electron's spin - which can move either up or down. The time taken for such manipulation is about 1 to 20 nanoseconds (corresponding to a frequency of 1GHz), but scientists are confident that this time can be decreased further.
When such a fast switching between up and down spin is possible, it should give rise to new devices based on the spins of single electrons. For example, one could have memories where each bit is stored in the spin of a trapped electron, whereas in today's memories, the bit is represented by the collective charge of millions of electrons:D. These spintronic devices would be 1000 fold smaller than their electronic counterparts, consume less energy, and lead to quantum and optical computers.