Abstract
A spin-1/2 triangular-lattice antiferromagnet is a prototypical frustrated quantum magnet, which exhibits remarkable quantum many-body effects that arise from the synergy between geometric spin frustration and quantum fluctuations. It can host quantum frustrated magnetic topological phenomena such as quantum spin liquid (QSL) states, highlighted by the presence of fractionalized quasiparticles within a continuum of magnetic excitations. In this work, we use neutron scattering to study CoZnMo3O8, which has a triangular lattice of Jeff=1/2Co2+ ions with octahedral coordination. We found a wave-vector-dependent excitation continuum at low energy that disappears with increasing temperature. Although these excitations are reminiscent of a spin excitation continuum in a QSL state, their presence in CoZnMo3O8 originates from magnetic intersite disorder-induced dynamic spin states with peculiar excitations. Our results, therefore, provide direct experimental evidence for the presence of a disorder-induced spin excitation continuum.
| Original language | English |
|---|---|
| Article number | 024431 |
| Journal | Physical Review B |
| Volume | 108 |
| Issue number | 2 |
| DOIs | |
| State | Published - Jul 1 2023 |
Funding
The INS work at Rice is supported by the U.S. DOE, BES under Grant No. DE-SC0012311 (P.D.). The single-crystal growth and characterization efforts at Rice are supported by the Robert A. Welch Foundation Grant No. C-1839 (P.D.). A portion of this research used resources at the Spallation Neutron Source, a DOE Office of Science User Facility operated by ORNL. We thank Dr. M.-K. Lee and C.-C. Yang at PPMS-16T and SQUID VSM Labs, Instrumentation Center, National Cheng Kung University (NCKU) for technical support. C.L.H. is supported by the Ministry of Science and Technology in Taiwan (Grants No. MOST 109-2112-M-006-026-MY3 and No. MOST 110-2124-M-006-009). Access to MACS was provided by the Center for High Resolution Neutron Scattering, a partnership between the National Institute of Standards and Technology and the National Science Foundation under Agreement No. DMR-1508249. E.F. and H.C. acknowledge support from the U.S. Department of Energy (DOE), Office of Science, Office of Basic Energy Sciences, Early Career Research Program Award No. KC0402020, under Contract No. DE-AC05-00OR22725. The work at Rutgers University was supported by the DOE under Grant No. DOE: DE-FG02-07ER46382. The identification of any commercial product or trade name does not imply endorsement or recommendation by the National Institute of Standards and Technology. DFT calculations were performed using the Wake Forest University (WFU) High Performance Computing Facility, a centrally managed computational resource available to WFU researchers including faculty, staff, students, and collaborators .