October 11, 2016 - The theories recognized with this year’s Nobel Prize in Physics underpin research ongoing at the Department of Energy’s Oak Ridge National Laboratory, where scientists are using neutrons as a probe to seek new materials with extraordinary properties for applications such as next-generation electronics, superconductors, and quantum computing.
David Thouless, Duncan Haldane, and Michael Kosterlitz were awarded the Nobel for work begun in the early 1970s that applied a branch of mathematics called topology to study unusual phases or states of matter. Topology describes properties that only change in integer steps, illustrated at the Nobel announcement by a cinnamon bun, bagel, and pretzel that, topologically, vary only in their number of holes, rather than physical characteristics like taste, texture, or mass.
“The Nobel committee recognized that the theoretical groundwork laid by scientists helped us to understand the behavior of collective quantum states in a profoundly new way,” said Stephen Nagler, director of the Quantum Condensed Matter Division at ORNL. “The neutrons generated for research by the Spallation Neutron Source and High Flux Isotope Reactor provide a uniquely powerful tool for exploring these states to further advance our understanding.”
SNS and HFIR are DOE Office of Science User Facilities that provide powerful instrument suites to researchers from around the world for research including the fields that hold great promise thanks to the work of this year’s Nobel winners.
In one application, Kosterlitz and Thouless used topology to overturn the prevailing theory that superconductivity wasn’t possible in thin layers, or at low temperatures.
“Understanding the topological quantum behavior is precisely the kind of problems we try to solve,” said Arnab Banerjee, a postdoctoral researcher in ORNL’s Quantum Condensed Matter Division. “Our work attempts to give shape to the mathematics that these Nobel laureates and others have been developing in real materials.”
Haldane’s work in particular, Banerjee says, was a strong prerequisite for the work he and Nagler’s group recently conducted involving 2-D spin liquids, which was also based largely on prior research by Alexei Kitaev, now famously known for the elusive Kitaev Majorana Fermion. The concept of Kitaev quantum spin liquids, in fact, was also motivated by the work of Kosterlitz and Thouless, Banerjee said.
“The work the Nobel winners did made the road smoother for some of Kitaev’s ideas, and hence, also our own,” Banerjee said.
Today, neutron scattering is a powerful tool used to measure and detect the properties and behaviors of many exotic quantum states of matter in a wide range of materials and applications. Some of QCMD’s most recent and impactful research in the field include:
- ORNL Neutron ‘Splashes’ Reveal Signature of Exotic Particles
- Neutrons Tap Into Magnetism in Topological Insulators at High Temperatures
- Neutrons Reveal Unexpected Magnetism in Rare-Earth Alloy
- ORNL Research Finds Magnetic Material Could Host Wily Weyl Fermions
- Two Spin Liquids Square Off in an Iron-Based Superconductor
“When the SNS was first proposed it was realized we would need its unique capabilities to understand quantum effects like those proposed by the Nobel Prize winners,” said Alan Tennant, Chief Scientist of ORNL’s Neutron Sciences Directorate. “It’s exciting to see all the new discoveries being made. These effects have huge potential for future applications, which has made the case for us to build a second target station that will have the power to look at these materials closer than ever before.”
The Spallation Neutron Source and the High Flux Isotope Reactor are DOE Office of Science User Facilities. UT-Battelle manages ORNL for the DOE's Office of Science. The Office of Science is the single largest supporter of basic research in the physical sciences in the United States, and is working to address some of the most pressing challenges of our time. For more information, please visit http://energy.gov/science/.