Hierarchy of Exchange Interactions in the Triangular-Lattice Spin Liquid YbMgGaO_{4}
The spin-1/2 triangular lattice antiferromagnet YbMgGaO_{4} has attracted attention recently as a quantum spin-liquid candidate with the possible presence of off-diagonal anisotropic exchange interactions induced by spin-orbit coupling. Whether a quantum spin liquid is stabilized or not depends on t...
| Main Authors: | , , , , , , , , , |
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| Format: | Article |
| Language: | English |
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American Physical Society
2018-07-01
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| Series: | Physical Review X |
| Online Access: | http://doi.org/10.1103/PhysRevX.8.031001 |
| _version_ | 1818743449344540672 |
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| author | Xinshu Zhang Fahad Mahmood Marcus Daum Zhiling Dun Joseph A. M. Paddison Nicholas J. Laurita Tao Hong Haidong Zhou N. P. Armitage Martin Mourigal |
| author_facet | Xinshu Zhang Fahad Mahmood Marcus Daum Zhiling Dun Joseph A. M. Paddison Nicholas J. Laurita Tao Hong Haidong Zhou N. P. Armitage Martin Mourigal |
| author_sort | Xinshu Zhang |
| collection | DOAJ |
| description | The spin-1/2 triangular lattice antiferromagnet YbMgGaO_{4} has attracted attention recently as a quantum spin-liquid candidate with the possible presence of off-diagonal anisotropic exchange interactions induced by spin-orbit coupling. Whether a quantum spin liquid is stabilized or not depends on the interplay of various exchange interactions with chemical disorder that is inherent to the layered structure of the compound. We combine time-domain terahertz spectroscopy and inelastic neutron scattering measurements in the field-polarized state of YbMgGaO_{4} to obtain better insight of its exchange interactions. Terahertz spectroscopy in this fashion functions as a high-field electron spin resonance and probes the spin-wave excitations at the Brillouin zone center, ideally complementing neutron scattering. A global spin-wave fit to all our spectroscopic data at fields over 4 T, informed by the analysis of the terahertz spectroscopy linewidths, yields constraints on the disorder-averaged g factors and exchange interactions. Our results paint YbMgGaO_{4} as an easy-plane XXZ antiferromagnet with the combined and necessary presence of subleading next-nearest neighbor and weak anisotropic off-diagonal nearest-neighbor interactions. Moreover, the obtained g factors are substantially different from previous reports. This work establishes the hierarchy of exchange interactions in YbMgGaO_{4} from high-field data alone and thus strongly constrains possible mechanisms responsible for the observed spin-liquid phenomenology. |
| first_indexed | 2024-12-18T02:28:35Z |
| format | Article |
| id | doaj.art-b168b05561e9439981199ad89579ab4f |
| institution | Directory Open Access Journal |
| issn | 2160-3308 |
| language | English |
| last_indexed | 2024-12-18T02:28:35Z |
| publishDate | 2018-07-01 |
| publisher | American Physical Society |
| record_format | Article |
| series | Physical Review X |
| spelling | doaj.art-b168b05561e9439981199ad89579ab4f2022-12-21T21:23:58ZengAmerican Physical SocietyPhysical Review X2160-33082018-07-018303100110.1103/PhysRevX.8.031001Hierarchy of Exchange Interactions in the Triangular-Lattice Spin Liquid YbMgGaO_{4}Xinshu ZhangFahad MahmoodMarcus DaumZhiling DunJoseph A. M. PaddisonNicholas J. LauritaTao HongHaidong ZhouN. P. ArmitageMartin MourigalThe spin-1/2 triangular lattice antiferromagnet YbMgGaO_{4} has attracted attention recently as a quantum spin-liquid candidate with the possible presence of off-diagonal anisotropic exchange interactions induced by spin-orbit coupling. Whether a quantum spin liquid is stabilized or not depends on the interplay of various exchange interactions with chemical disorder that is inherent to the layered structure of the compound. We combine time-domain terahertz spectroscopy and inelastic neutron scattering measurements in the field-polarized state of YbMgGaO_{4} to obtain better insight of its exchange interactions. Terahertz spectroscopy in this fashion functions as a high-field electron spin resonance and probes the spin-wave excitations at the Brillouin zone center, ideally complementing neutron scattering. A global spin-wave fit to all our spectroscopic data at fields over 4 T, informed by the analysis of the terahertz spectroscopy linewidths, yields constraints on the disorder-averaged g factors and exchange interactions. Our results paint YbMgGaO_{4} as an easy-plane XXZ antiferromagnet with the combined and necessary presence of subleading next-nearest neighbor and weak anisotropic off-diagonal nearest-neighbor interactions. Moreover, the obtained g factors are substantially different from previous reports. This work establishes the hierarchy of exchange interactions in YbMgGaO_{4} from high-field data alone and thus strongly constrains possible mechanisms responsible for the observed spin-liquid phenomenology.http://doi.org/10.1103/PhysRevX.8.031001 |
| spellingShingle | Xinshu Zhang Fahad Mahmood Marcus Daum Zhiling Dun Joseph A. M. Paddison Nicholas J. Laurita Tao Hong Haidong Zhou N. P. Armitage Martin Mourigal Hierarchy of Exchange Interactions in the Triangular-Lattice Spin Liquid YbMgGaO_{4} Physical Review X |
| title | Hierarchy of Exchange Interactions in the Triangular-Lattice Spin Liquid YbMgGaO_{4} |
| title_full | Hierarchy of Exchange Interactions in the Triangular-Lattice Spin Liquid YbMgGaO_{4} |
| title_fullStr | Hierarchy of Exchange Interactions in the Triangular-Lattice Spin Liquid YbMgGaO_{4} |
| title_full_unstemmed | Hierarchy of Exchange Interactions in the Triangular-Lattice Spin Liquid YbMgGaO_{4} |
| title_short | Hierarchy of Exchange Interactions in the Triangular-Lattice Spin Liquid YbMgGaO_{4} |
| title_sort | hierarchy of exchange interactions in the triangular lattice spin liquid ybmggao 4 |
| url | http://doi.org/10.1103/PhysRevX.8.031001 |
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