Original URL: http://www.theregister.co.uk/2005/02/01/transistor_replacement/

HP scientists wave bye-bye to the transistor

So last century

By Lucy Sherriff

Posted in Science, 1st February 2005 15:14 GMT

A breakthrough in molecular computing could be the beginning of the end for the transistor, according to scientists at HP.

Researchers have successfully demonstrated a "crossbar latch", a technology that behaves just like a transistor, but is much smaller, and simpler to make. HP's quantum science research (QSR) group says the new technology paves the way for machines that are thousands of times more powerful than anything available today.

The device, based on just three wires, can perform the NOT, AND and OR operations. It can also restore the logic level in a circuit to its ideal voltage value, according to the research paper, published in today's Journal of Applied Physics.

The "crossbar latch" has a significant advantage over traditional silicon transistors, the QSR team explains. Standard semiconductor circuits need three-terminal transistors to perform the NOT operation and restore signals. But the performance of silicon components is limited by their size, and silicon transistors of just a few nanometres across are not expected to be operable.

The latch is composed of a single wire that behaves as a signal line, crossed by two control lines. These control lines have an electronically switchable, molecular scale junction, where they intersect the signal line. It is controlled by applying a sequence of voltage impulses to the control lines and using oppositely polarised switches.

"Transistors will continue to be used for years to come with conventional silicon circuits," said Phil Kuekes, senior computer architect, QSR, and one of the paper's authors. "But this could someday replace transistors in computers, just as transistors replaced vacuum tubes and vacuum tubes replaced electromagnetic relays before them."

Kukes was awarded a US patent (No. 6,586,965) on the technology in 2003. ®

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