AsianScientist (Jan. 6, 2012) – The narrowest conducting wires in silicon ever made – just four atoms wide and one atom tall – have been shown to have the same electrical current carrying capability of copper, according to a new study published today in the journal Science.
Despite their astonishingly tiny diameter – 10,000 times thinner than a human hair – these wires have exceptionally good electrical properties, raising hopes they will serve to connect atomic-scale components in the quantum computers of tomorrow.
“Interconnecting wiring of this scale will be vital for the development of future atomic-scale electronic circuits,” said lead author Bent Weber, a PhD student in the ARC Center of Excellence for Quantum Computation and Communication Technology at Australia’s University of New South Wales.
The wires were made by precisely placing chains of phosphorus atoms within a silicon crystal, made possible using a technique called scanning tunneling microscopy. This technique not only allowed the team to image individual atoms but also to manipulate them and place them in position, Weber explained.
The researchers discovered that the electrical resistivity of their wires – a measure of the ease with which electrical current can flow – does not depend on the wire width. Their behavior is described by Ohm’s law, which is a fundamental law of physics taught to every high school student.
“It is extraordinary to show that such a basic law still holds even when constructing a wire from the fundamental building blocks of nature – atoms,” Weber said.
The discovery demonstrates that electrical interconnects in silicon can shrink to atomic dimensions without loss of functionality, said the Center’s Director and senior author, Professor Michelle Simmons.
The findings also imply that computer chips may someday be even tinier in size, she added, allowing ever smaller and more powerful computers.
“It will come down to the wire. We are on the threshold of making transistors out of individual atoms. But to build a practical quantum computer we have recognised that the interconnecting wiring and circuitry also needs to shrink to the atomic scale,” she said.
The article can be found at: Weber B et al. (2012) Ohm’s Law Survives to the Atomic Scale.
——
Source: UNSW.
Disclaimer: This article does not necessarily reflect the views of AsianScientist or its staff.
