Researchers at Columbia University
and University of California, San Diego, have introduced a novel
“multi-messenger” approach to quantum physics that signifies a technological
leap in how scientists can explore quantum materials.
The findings
appear in a recent article published in Nature Materials,
led by A. S. McLeod, postdoctoral researcher, Columbia Nano Initiative, with
co-authors Dmitri Basov and A. J. Millis at Columbia and R.A. Averitt at UC San
Diego.
“We have brought a technique from
the inter-galactic scale down to the realm of the ultra-small,” said 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 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 using only one type of
spectroscopy. The researchers have shown 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. When thin films of metal oxide are subject to a unique
strain, ultra-fast light pulses can trigger the material to switch into an
unexplored phase of nanometer-scale domains, and the change is reversible.
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 light-triggered domains with nanometer-scale
precision.
The study reveals how unanticipated
properties can emerge in long-studied quantum materials at ultra-small scales
when scientists tune them by strain.
“It is relatively common to study
these nano-phase materials with scanning probes. But this is the first time an
optical nano-probe has been combined with simultaneous magnetic nano-imaging,
and all at the very low temperatures where quantum materials show their
merits,” McLeod said. “Now, investigation of quantum materials by multi-modal nanoscience
offers a means to close the loop on programs to engineer them.”
Source:
Journal
article: https://www.nature.com/articles/s41563-019-0533-y
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