Working transistor created from a single atom

Physicists in the U.S. and Australia have jointly created a working transistor from a single phosphorus atom embedded in a silicon crystal.

The discovery lays the groundwork for a quantum computer that would be much smaller and faster than today’s silicon-based devices. The physicists who made the discovery are based at Purdue University in West Lafayette, Indiana and the University of New South Wales in Sydney, Australia.

Unlike conventional computers that are based on transistors with distinct “on” and “off” or “1” and “0” modes, quantum computers are built from devices called qubits. A qubit can represent a multiplicity of values simultaneously.

“This is at least a 10-year effort to make very tiny electrical wires and combine them with the placement of a phosphorous atom exactly where they want them,” IBM physicist Andreas Heinrich told the "New York Times" about the discovery.

While the research is a significant step toward making a functioning quantum computing system, it remains unclear whether the technology can be harnessed for useful tasks. The work, the newspaper reported, demonstrated the fundamental limits of the miniaturization of computers.

“It shows that Moore’s Law can be scaled toward atomic scales in silicon,” Gerhard Klimeck, professor of electrical and computer engineering at Purdue, told the “Times.” “The technologies for classical computing can survive to the atomic scale.”

The researchers said had also made it possible to read and write information from the tiniest-conceivable switch. Before the discovery, single atom transistors were created on a hit or miss basis.

Last January, the same researchers reported in the journal Science that they were able to create silicon nanowires that were just a single atom thick and four atoms wide by assembling thin strands of phosphorous atoms. Combining the two technologies indicates they have made progress at assembling the basic building blocks of a new ultra-small generation of nanoelectronics.

The results of the latest discovery were also reported in the journal, Nature Nanotechnology.