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After the Transistor, a Leap Into the Microcosm

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Silicon Nanowires

A crop of silicon nanowires growing under a transmission electron microscope. The gray columns are the wires, and the black, liquid droplet on top of each catalyzes the growth.


Gaze into the electron microscope display in Frances Ross’s laboratory here and it is possible to persuade yourself that Dr. Ross, a 21st-century materials scientist, is actually a farmer in some Lilliputian silicon world.

Dr. Ross, an I.B.M researcher, is growing a crop of mushroom-shaped silicon nanowires that may one day become a basic building block for a new kind of electronics. Nanowires are just one example, although one of the most promising, of a transformation now taking place in the material sciences as researchers push to create the next generation of switching devices smaller, faster and more powerful than today’s transistors.

The reason that many computer scientists are pursuing this goal is that the shrinking of the transistor has approached fundamental physical limits. Increasingly, transistor manufacturers grapple with subatomic effects, like the tendency for electrons to “leak” across material boundaries. The leaking electrons make it more difficult to know when a transistor is in an on or off state, the information that makes electronic computing possible. They have also led to excess heat, the bane of the fastest computer chips.

The transistor is not just another element of the electronic world. It is the invention that made the computer revolution possible. In essence it is an on-off switch controlled by the flow of electricity. For the purposes of computing, when the switch is on it represents a one. When it is off it represents a zero. These zeros and ones are the most basic language of computers.

From The New York Times
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