Quantum Study Reveals Potential for Sensing at the Nanoscale

Quantum nanometrology just got a step closer

Published: Wednesday, September 13, 2023 - 10:58

(ORNL: Oak Ridge, TN) -- A new nanoscience study led by a researcher at the U.S. Department of Energy’s Oak Ridge National Laboratory takes a big-picture look at how scientists study materials at the smallest scales.

The paper, published in Science Advances, reviews leading work in subsurface nanometrology, the science of internal measurement at the nanoscale level, and suggests quantum sensing could become the foundation for the field’s next era of discoveries. Potential applications could range from mapping intracellular structures for targeted drug delivery to characterizing quantum materials and nanostructures for advancing quantum computing.

“Our goal was to define the state of the art and to consider what’s been done and where we need to go,” says Ali Passian, an ORNL senior research scientist and senior author of the study.

“Everybody wants to know what’s below the surface of materials. But finding out what’s really there tends to be incredibly challenging at any scale. We hope to inspire a new generation of scientists to tackle this challenge by exploiting quantum phenomena or whatever the most promising opportunities may be so we can push the boundaries of sensing and imaging science toward greater discoveries and understanding.”

Particles at the nanoscale act as the building blocks of quantum science—just small enough to enable scientists to tweak major properties of materials with maximum precision. One nanometer equals a billionth of a meter, a millionth of a millimeter, and a thousandth of a micrometer. The average sheet of paper, for example, runs about 100,000 nanometers thick.

Passian and co-author Amir Payam of Ulster University suggest the nanoscale level may be not only where intricate molecular assemblies of biological systems such as cell membranes form but also where the dimensions of emerging materials such as metasurfaces and quantum materials align. So far, it’s an underexplored opportunity, they conclude.

Breakthrough tools like the scanning probe microscope, which uses a sharp-tipped probe to inspect samples at the atomic level, have helped speed advances in the nanometrology of surfaces. Subsurface studies have achieved fewer comparable breakthroughs, the authors note.

“All of our senses are geared toward surfaces,” Passian says. “Though still difficult, we have extended our reach to the nanoscale by somehow disturbing the material using light, sound, electrons, and tiny needles. But once there, measuring what’s beneath remains extremely challenging. We need new methods that allow us to peer inside these materials while leaving them intact. Quantum science may offer opportunities here, particularly quantum sensing, where, for example, the quantum states of the probe, the light, and the sample could be capitalized upon.”

The authors suggest quantum sensing techniques now in the early stages of development could hold the key to advances in subsurface exploration. Quantum probes, for example, could employ skyrmions—subatomic quasiparticles created by disruptions in magnetic fields and already under consideration for other quantum applications—to probe deeper than any current technique allows.

“People are working hard to push the limits of detection and create new measurement modalities,” Passian says. “I think the next few years will be exciting in terms of materialization and user-friendly implementation of these techniques toward achieving quantum nanometrology of surfaces and the subsurface regions.”

Support for this work came from the Biological and Environmental Research program in the U.S. Department of Energy’s Office of Science and from Northern Ireland’s Department of Economy through a U.S.-Ireland R&D partnership grant.

The University of Tennessee-Battelle manages ORNL for the Office of Science, the single largest supporter of basic research in the physical sciences in the United States. The Office of Science is working to address some of the most pressing challenges of our time. For more information, visit https://energy.gov/science. 

About The Author

Oak Ridge National Laboratory

Oak Ridge National Laboratory is a multiprogram science and technology laboratory managed for the U.S. Department of Energy by the University of Tennessee-Battelle LLC. Scientists and engineers at ORNL conduct basic and applied research and development to create scientific knowledge and technological solutions that strengthen the nation's leadership in key areas of science; increase the availability of clean, abundant energy; restore and protect the environment; and contribute to national security.