Control at the Nanoscale
Quantum Mechanics Enables Control at the Nanoscale
Self-assembly is vital in order to enable industrial scale manufacturing on the atomic scale, because existing technologies usually rely on processes that involve manipulation of tiny individual building blocks. Those processes are time consuming and therefore expensive.
The experimental work was done by Postdoctoral researcher Pawel Kowalczyk and PhD student Ojas Mahapatra in Prof. Simon Brown’s group at the University of Canterbury and was largely funded by the MacDiarmid Institute for Advanced Materials and Nanotechnology, but the project was an international one, involving researchers the United States and China. Prof. Brown said, “the international collaboration was key to developing a detailed understanding of the mechanisms of self-assembly”.
Anyone who has played a musical instrument, or blown across the open end of a bottle or a pipe, knows that the musical note that is produced depends on the length of the instrument. In fact to get a nice musical note the length of the pipe must be just right: it should match the wavelength of the note required. In this research it was discovered that – because of the way quantum mechanics works – the opposite process comes into play on the nanoscale i.e. it was discovered that the structure tunes its size to match the wavelength of the electron waves inside it.
The new research, published recently in the prestigious international journal Nano Letters, shows that the sizes of nanostructures can be controlled by the wavelength of the electrons in the material. Structures with sizes that match the wavelength of the electrons turn out to be more stable, and are therefore preferred. This opens the way to tuning the sizes of many nanostructures by first tuning the wavelengths of their electrons.
Prof Brown said “what made this work really complicated was that there are several different electronic effects happening at the same time – the collaboration with Prof Tai Chiang’s group at the University of Illinois at Urbana Champaign, who were able to calculate the electron’s behaviour, was what allowed us to understand this complex puzzle.”