A Quantum Breakthrough Brings a Technique From Astronomy to the Nano-scale
Researchers at Columbia University and the University of California San Diego have introduced a “multi-messenger” approach to quantum physics that signifies a technological leap in how scientists can explore quantum materials.
“We have brought a technique from the inter-galactic scale down to the realm of the ultra-small,” said Dmitri Basov, Higgins Professor of Physics and director of the Energy Frontier Research Center at Columbia. “Equipped with multi-modal nanoscience tools we can now routinely go places no one thought would be possible as recently as five years ago.”
The findings appear in a recent article published in Nature Materials, led by A. S. McLeod, postdoctoral researcher, Columbia Nano Initiative, with co-authors Basov, A. J. Millis, at Columbia, and R.A. Averitt at UC San Diego.
The work was inspired by multi-messenger astrophysics, which emerged during the last decade as a revolutionary technique for the study of distant phenomena like black hole mergers. Simultaneous measurements from instruments, including infrared, optical, X-ray and gravitational-wave telescopes can, taken together, deliver a physical picture greater than the sum of their individual parts.
The search is on for new materials that can supplement the current reliance on electronic semiconductors. Control over material properties using light can offer improved functionality, speed, flexibility and energy efficiency for next-generation computing platforms.
Experimental papers on quantum materials have typically reported results obtained by employing only one type of spectroscopy. This study shows the power of using a combination of measurement techniques to simultaneously examine electrical and optical properties.
The researchers performed their experiment by focusing laser light onto the sharp tip of a needle probe coated with magnetic material, which becomes an antenna that delivers a high-intensity light pulse to the region of the sample underneath. The light pulse triggers a transition into a new phase of matter, creating a nanometer-scale region with new properties.
By scanning the probe over the surface of their thin-film sample, the researchers were able to trigger the change locally and simultaneously manipulate and record the electrical, magnetic and optical properties of these regions with nanometer-scale precision.
The study reveals how unanticipated properties can emerge in long-studied quantum materials at ultra-small scales.
“It is relatively common to study these materials with scanning probes. But this is the first time an optical nano-probe has been combined with magnetic nano-imaging, and all at the very low temperatures where quantum materials show their merits,” said McLeod. “Now, investigation of quantum materials by multi-modal nanoscience offers a means to close the loop on programs to engineer them.”
The study, “Multi-messenger nanoprobes of hidden magnetism in a strained manganite,” was developed with support from Programmable Quantum Materials, an Energy Frontier Research Center funded by the United States Department of Energy (DOE), Office of Science and Basic Energy Sciences.
— Carla Cantor, Columbia News