A team of scientists at Griffith University collaborating with Australia's Commonwealth Scientific and Industrial Research Organization (CSIRO) has revealed an impressively accurate method for scientific measurements which utilizes a single atom as the sensor, with sensitivity down to 100 zeptoNewtons.
Using extremely miniaturized segmented-style Fresnel lenses - the same design used in lighthouses for over a century - which enable remarkably superior-quality images of a single atom, the researchers have been able to identify position displacements with nanometer precision in three dimensions.
Our atom is missing one electron, so it's very sensitive to electrical fields. By measuring the displacement, we've built a very sensitive tool for measuring electrical forces.
100 zeptoNewtons is a very small force. That's about the same as the force of gravity between a person in Brisbane and a person in Canberra. It can be used to investigate what's occurring on surfaces, which will help miniaturize ion trap type quantum computers and other quantum devices.
Dr. Erik Streed, Centre for Quantum Dynamics
Since 2011, the Griffith team has been spearheading the application of such lenses in quantum physics, but this is the first time they have been applied to attain such high levels of accuracy in sensing the forces impacting a particular atom.
By deliberately moving their optics marginally out of focus, the scientists could successfully measure displacements in all three dimensions, with the third direction established when the atom was shifting back into focus or further away from focus.
Along with the research's applications for central physics of atomic, magnetic, quantum, and surface phenomena, Dr. Streed is also working as part of Griffith's Institute for Glycomics to adopt these kinds of quantum technologies for biological and medical research.
"With the Institute for Glycomics I'm also interested in developing this into a tool to measure the electrical fields outside a single isolated biomolecule, like the dipole moment, as a new way to help understand how they behave," he said.
The sharp accuracy of the method is precisely because of the use of a single atom as a 'probe' in attaining these measurements. Earlier methods similar to this used a number of atoms as the electric force sensor and were restricted to only one dimension.
The Australian Research Council, the CSIRO Manufacturing facility at Pullenvale, Queensland, Griffith University, and the Australian Government Research Training Program Scholarship supported this research financially.