HOUSTON -- (July 15, 2019) -- There's no known way to prove a three-dimensional "quantum spin liquid" exists, so Rice University physicists and their collaborators did the next best thing: They showed their single crystals of cerium zirconium pyrochlore had the right stuff to qualify as the first possible 3D version of the long-sought state of matter.
In a paper this week in Nature Physics, researchers offered a host of experimental evidence -- including crucial neutron-scattering experiments at Oak Ridge National Laboratory (ORNL) and muon spin relaxation experiments at Switzerland's Paul Scherrer Institute (PSI) -- to support their case that cerium zirconium pyrochlore, in its single-crystal form, is the first material that qualifies as a 3D quantum spin liquid.
"A quantum spin liquid is something that scientists define based on what you don't see," said Rice's Pengcheng Dai, corresponding author of the study and a member of Rice's Center for Quantum Materials (RCQM).
"In a solid with a periodic arrangement of spins, if you know what a spin is doing over here, you can know what a spin is doing many, many repetitions away because of long-range order," said Rice theoretical physicist and study co-author Andriy Nevidomskyy, an associate professor of physics and astronomy and RCQM member.
The research was supported by the Department of Energy (BES DE-SC0012311, BES DE-SC0019503, BES DE-FG02-04ER46105, BES KC0402010 and DE-AC05-00OR22725), the Robert A. Welch Foundation (C-1839 and C-1818), the National Science Foundation (DMR-1350237), the National Research Foundation of Korea (NRF-2017K1A3A7A09016303), Rutgers University, the Gordon and Betty Moore Foundation's EPiQS initiative (GBMF6402) and the Ministry of Science and Technology of China (2016YFA0301001 and IMAGES are available for download at: https:/ A 3D representation of the spin-excitation continuum -- a possible hallmark of a quantum spin liquid -- observed in a single crystal sample of cerium zirconium pyrochlore in experiments at Oak Ridge National Laboratory (ORNL).
(Image by Tong Chen/Rice University) https:/ Rice University physicists (from left) Tong Chen, Pengcheng Dai, David Tam, Andriy Nevidomskyy, Bin Gao and Emilia Morosan are co-authors of a Nature Physics study that found single crystals of cerium zirconium pyrochlore to be the first possible 3D quantum spin liquid, a material first theorized in 1973.