Transform the Properties of Matter

The Penn physicists are among many modern researchers who have been experimenting with a different way of transforming matter through artificial solids, formed from closely packed nanoscale crystals, also called "quantum dots."

"Essentially, we're forming artificial solids from artificial atoms – about 10 times larger than real atoms – whose properties we can fine tune on the quantum level," said Marija Drndic, an assistant professor in Penn's Department of Physics and Astronomy. "Artificial solids are expected to revolutionize the fabrication of electronic devices in the near future, but now we are only beginning to understand their fundamental behaviour."

Artificial solids, in general, are constructed by specifically assembling a number of nanocrystals, each composed of only a few thousand atoms, into a closely packed and well-ordered lattice. Previous researchers have demonstrated that quantum dots can be manipulated to change their physical properties, particularly their optical properties.

In their study, Drndic and her colleagues looked at the ability of artificial solids to transport electrons. They demonstrated that, by controlling the coupling of artificial atoms within the crystal, they could increase the electrical conductivity of the entire crystal. According to the researchers, this system promises the possibility of designing artificial solids that can be switched through a variety of electronic phase transitions, with little influence from the local environment. Their findings represent a key step towards the fabrication of functional nanocrystal-based devices and circuits.; Source: University of Pennsylvania