Possible Observation of Quadrupole Waves in Spin Nematics
Discovery of new states of matter is a key objective in modern condensed matter physics, which often leads to revolutionary technological advancements such as superconductivity. Quantum spin nematic, a "hidden order" that evades conventional magnetic probes, is one such state. Na_{2}BaNi(PO_{4})_{2} is a potential spin nematic material, suggested by the observation of a two-magnon Bose-Einstein condensation from above the saturation field. However, direct confirmation of the spin nematicity remains elusive. This Letter presents inelastic neutron scattering spectra from the putative spin nematic phases of Na_{2}BaNi(PO_{4})_{2}, revealing low-energy quadrupole waves that are absent in the neighboring conventional magnetic phases. A spin-one model quantitatively captures the full details of the spin excitation spectra across all low-temperature phases, providing direct evidence of the spin nematic orders. Additionally, we show evidence of the three-magnon continuum and two-magnon bound states in the 1/3-magnetization plateau, revealing condensation of the two-magnon bound state as the origin of the low-field spin nematic supersolid phase.
Authors
- Huiqiu Yuan (ORCID: https://orcid.org/0000-0002-9787-4884)
- Dehong Yu (ORCID: https://orcid.org/0000-0003-2995-0336)
- Naoki Murai
- Haijun Liao (ORCID: https://orcid.org/0000-0002-2624-8691)
- A. Podlesnyak (ORCID: https://orcid.org/0000-0001-9366-6319)
- Tao Xiang (ORCID: https://orcid.org/0000-0001-5998-7338)
- Seiko Ohira‐Kawamura (ORCID: https://orcid.org/0000-0001-5900-7053)
- Zhentao Wang (ORCID: https://orcid.org/0000-0001-7442-2933)
- Ling Wang (ORCID: https://orcid.org/0000-0001-5601-7539)
- Jieming Sheng (ORCID: https://orcid.org/0000-0003-4462-1661)
- Pharit Piyawongwatthana (ORCID: https://orcid.org/0000-0001-9094-4520)
- Jia‐Wei Mei (ORCID: https://orcid.org/0000-0003-4933-4880)
- Le Wang (ORCID: https://orcid.org/0000-0002-1962-3510)
- Liusuo Wu (ORCID: https://orcid.org/0000-0003-0103-5267)
- Xiang Shi
- Jiahang Hu
- Lei Xu (ORCID: https://orcid.org/0000-0002-4925-6133)
- Runze Chi (ORCID: https://orcid.org/0009-0006-4194-0527)
Institutions
- Japan Atomic Energy Agency (JP)
- California Institute of Technology (US)
- Oak Ridge National Laboratory (US)
- Australian Nuclear Science and Technology Organisation (AU)
- Shenzhen Institute of Information Technology (CN)
- Chinese Academy of Sciences (CN)
- Bay Institute (US)
- Southern University of Science and Technology (CN)
- Songshan Lake Materials Laboratory (CN)
- Institute for Advanced Study (DE)
- Beijing Academy of Quantum Information Sciences (CN)
- Institute of Physics (CN)
- University of Chinese Academy of Sciences (CN)
- Quantum Science Center of Guangdong-Hong Kong-Macao Greater Bay Area (CN)
- Zhejiang University (CN)
Publication Details
- Journal
- Physical Review Letters
- Published
- 2025-10-09
- DOI
- https://doi.org/10.1103/pywx-vxfh
- Citations
- 2
- Primary Topic
- Physics of Superconductivity and Magnetism
- Type
- article
- Field-Weighted Citation Impact
- 2.52