An Indian origin researcher at Stanford University has shown that two nanostructures with different shapes can produce exactly the same sound, a finding that may influence real nano-electronic systems significantly.
Washington, February 9 : An Indian origin researcher at Stanford University has shown that two nanostructures with different shapes can produce exactly the same sound, a finding that may influence real nano-electronic systems significantly.
Physicist Hari Manoharan calls this phenomenon isospectrality.
His work is a follow-up to a mathematical study of the Nineties that proved that two drums of different shapes could produce the same sound.
However, the outcome of that study, which was physically verified, in one instance with vibrations on the surface of soap bubbles, raised theoretical questions about spectroscopy.
"This revolutionized our conception of the fundamental connections between shape and sound, but also had profound implications for spectroscopy in general, because it introduced an ambiguity," said Manoharan.
In the present study, Manoharan and his students took the drum question to a much lower level by investigating it in the quantum realm.
Using a tunneling scanning microscope and two roomfuls of equipment to move around individual carbon monoxide molecules on a copper surface, they built tiny walls only one-molecule high and shaped them into nine-sided enclosures that could resonate like drums. Manoharan called such enclosures quantum drums.
Each quantum drum had only 30 or so electrons inside, and they were walled in by about 100 carbon monoxide molecules.
Writing about their findings in the journal Science, the researchers revealed that two nanostructures with different shapes could resonate in the same way. They even created a video, complete with two quantum drums beating with the same sound.
Manoharan said that the practical value of having two different nanostructures with identical properties might lie in the design of ever-smaller computer chip circuits.
ANI