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Spin Doctor

Spin Doctor

According to professor of physics, Z. Valy Vardeny, an electron's spin-rather than its electrical charge-may be the key to unlocking cheaper and faster electronics and computers. Then it's only a matter of time before his organic spin valves will be widely available.

Present Position: Professor of Physics, University of Utah

Degrees: B.S., Ph.D. in physics, Technion (Israel Institute of Technology)

What are you trying to accomplish in your research? We are trying to build the first spin valves-at room temperature-from organic semiconductors.

What is "spintronics"? It's a buzz word meaning electronics based on the spin of electrons. Whereas computer memory stores data as zeroes and ones, spintronics stores data when electrons' spin (the angular momentum of a particle) is aligned all up or all down; think of it like a compass needle, pointing up or down. When a magnetic field in a device forces the electrons' spins to point all up or all down, it changes the resistance, enabling the device to control the flow of electrical current like a valve.

Where do organic semiconductors fit in? Semiconductors allow devices to emit light or carry electrons. Conventional semiconductors must be fabricated at high temperatures; organic semiconductor films and devices, though, can be fabricated at room temperature, which is more efficient. We used an organic semiconductor sandwiched between two ferromagnetic electrodes to make a three-layer organic spin valve. The two electrodes inject electrons with a particular spin direction into the semiconductor, which causes a change in electrical current when a magnetic field is applied.

Why might spintronics replace electronics in some cases? There is no "memory" attached to the electrical current. Spintronics is the only way to have electrical current "remember" how it was created. So this property can be written or read by a spin valve, and be used to create a memory chip.

To see a schematic drawing of an organic spin valve, go to http://rbi.ims.ca/3849-510. Contact Vardeny at [email protected].

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