A team, led by scientists at the University at Buffalo has revealed that they have identified the presence of a dynamic Jahn-Teller effect in defective diamonds, which will help advance the development of diamond-based systems in applications such as quantum information processing.
“We normally want things to be perfect, but defects are actually very important in terms of electronic applications,” said Peihong Zhang, the UB associate professor of physics who led the study.
“There are many proposals for the application of defective diamonds, ranging from quantum computing to biological imaging, and our research is one step toward a better understanding of these defect systems,” he stated.
The findings deal with diamonds whose crystal structure contains a particular defect: a nitrogen atom that sits alongside a vacant space in an otherwise perfect lattice made only of carbon.
At the point of the imperfection – the so-called “nitrogen-vacancy centre” – a single electron can jump between different energy states.
Understanding how the diamond system behaves when the electron rises to an excited state called a “3E” state is critical to the success of such proposed applications as quantum computing.
The problem is that at the nitrogen-vacancy center, the 3E state has two orbital components with exactly the same energy – a configuration that is inherently unstable.
In response, the lattice “stabilizes” by rearranging itself. Atoms near the nitrogen-vacancy centre move slightly, resulting in a new geometry that has a lower energy and is more stable.
This morphing is known as the Jahn-Teller effect, and until recently, the effect’s precise parameters in defective diamonds remained unknown.
Zhang and colleagues from the Rensselaer Polytechnic Institute in Troy, N.Y., are the first to crack that mystery.
The research was published online Sept. 30 in Physical Review Letters.