Nanoscale ‘Doughnuts’ May Lead to Materials for Quantum Information Processing

(Nanowerk) A method to tailor nanomaterials from the bottom up will make them more practical for applications like quantum information processing. By patterning nanoscale donuts into a two-dimensional crystal, researchers at Oak Ridge National Laboratory and their colleagues, including theoretical scientists at Rice’s Brown School of Engineering, have achieved a new level of control over its electrical and optical properties.
They are growing two-dimensional crystals over an array of micron-scale “donuts” and say these may lead to tailored materials for quantum information processing and other novel electronics.
“As the material grows over the topography of a donut, it creates localized strain,” Gupta said. “Strain in 2D material is beneficial because it allows us to tune its electronic properties, so we can change the bandgap at different places.”
The researchers discovered the height of the donuts affected the strain within and without, and even influencedthe crystal’s growth pattern. They found 40-nanometer donuts appeared to be the sweet spot for maximum strain in the hole. Above that, strain spread beyond the bumps and changed the crystal’s normal triangular growth pattern, causing the material to branch out.