Research delivers a quantum dot

researchers have witnessed the birth of a quantum dot and learned more about how such atomic islands form and grow, using the ultrahigh vacuum facility on campus.

This information will help researchers better understand and use materials that could lead to small, efficient and powerful computers, communication devices and scientific instruments.

Seongho Cho, Zhiming Wang, and Gregory Salamo report their findings in the upcoming issue of the journal Applied Physics Letters.

“We have changed the way people have to think about how nanostructures grow on a surface,” said Salamo, University Professor of physics. “People had a different idea of how these islands formed, but until now there was not direct evidence.”

The researchers combined the molecular-beam epitaxy machine, which creates material atom by atom, with scanning tunnelling microscopy, which can observe the atoms, to witness the creation of quantum dots, or atomic islands, of indium gallium arsenide (InGaAs) atoms atop a gallium arsenide (GaAs) surface. InGaAs is a material of electronic and optical interest for properties that could enhance communications equipment, computers and electronics.