Diffusive excitonic bands from frustrated triangular sublattice in a singlet-ground-state system

被引：9

作者：

Gao, Bin ^{[1
]}

Chen, Tong ^{[1
]}

Wu, Xiao-Chuan ^{[2
]}

Flynn, Michael ^{[3
,4
]}

Duan, Chunruo ^{[1
]}

Chen, Lebing ^{[1
]}

Huang, Chien-Lung ^{[1
,5
,6
]}

Liebman, Jesse ^{[1
]}

Li, Shuyi ^{[1
]}

Ye, Feng ^{[7
]}

Stone, Matthew B. ^{[7
]}

Podlesnyak, Andrey ^{[7
]}

Abernathy, Douglas L. ^{[7
]}

Adroja, Devashibhai T. ^{[8
]}

Duc Le, Manh ^{[8
]}

Huang, Qingzhen ^{[9
]}

Nevidomskyy, Andriy H. ^{[1
]}

Morosan, Emilia ^{[1
]}

Balents, Leon ^{[10
,11
]}

Dai, Pengcheng ^{[1
]}

机构：

[1] Rice Univ, Dept Phys & Astron, Houston, TX 77005 USA

[2] Univ Calif Santa Barbara, Dept Phys, Santa Barbara, CA 93106 USA

[3] Univ Calif Davis, Dept Phys, Davis, CA 95616 USA

[4] Boston Univ, Dept Phys, Boston, MA 02215 USA

[5] Natl Cheng Kung Univ, Dept Phys, Tainan 701, Taiwan

[6] Natl Cheng Kung Univ, Ctr Quantum Frontiers Res & Technol QFort, Tainan 701, Taiwan

[7] Oak Ridge Natl Lab, Neutron Scattering Div, Oak Ridge, TN 37831 USA

[8] Rutherford Appleton Lab, ISIS Neutron & Muon Source, Didcot OX11 0QX, England

[9] NIST, NIST Ctr Neutron Res, Gaithersburg, MD 20899 USA

[10] Univ Calif Santa Barbara, Kavli Inst Theoret Phys, Santa Barbara, CA 93106 USA

[11] Canadian Inst Adv Res, Toronto, ON, Canada

来源：

NATURE COMMUNICATIONS | 2023年 / 14卷 / 01期

关键词：

MAGNETIC EXCITATIONS;

D O I：

10.1038/s41467-023-37669-5

中图分类号：

O [数理科学和化学]; P [天文学、地球科学]; Q [生物科学]; N [自然科学总论];

学科分类号：

07 ; 0710 ; 09 ;

摘要：

Magnetic order in most materials occurs when magnetic ions with finite moments arrange in a particular pattern below the ordering temperature. Intriguingly, if the crystal electric field (CEF) effect results in a spin-singlet ground state, a magnetic order can still occur due to the exchange interactions between neighboring ions admixing the excited CEF levels. The magnetic excitations in such a state are spin excitons generally dispersionless in reciprocal space. Here we use neutron scattering to study stoichiometric Ni2Mo3O8, where Ni2+ ions form a bipartite honeycomb lattice comprised of two triangular lattices, with ions subject to the tetrahedral and octahedral crystalline environment, respectively. We find that in both types of ions, the CEF excitations have nonmagnetic singlet ground states, yet the material has magnetic order. Furthermore, CEF spin excitons from the tetrahedral sites form a dispersive diffusive pattern around the Brillouin zone boundary, likely due to spin entanglement and geometric frustrations. Some materials can display magnetic order despite having spin-singlet ground state on individual magnetic sites. This arises due to exchange interactions mixing excited crystal electric field states. Here, Gao et al study and example of such a system, Ni2Mo3O8, and find that crystal electric field states in both the paramagnetic and antiferromagnetic states exhibit dispersive excitations.

引用

页数：9

共 34 条

[1] Large easy-axis anisotropy in the one-dimensional magnet BaMo(PO4)2 [J].