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arXiv · 2112.11709

Neutron Scattering Studies of the Breathing Pyrochlore Antiferromagnet LiGaCr$_{4}$O$_{8}$

Zheng He·Yiqing Gu·Hongliang Wo·Yu Feng·Die Hu·Yiqing Hao·Yimeng Gu·Helen C. Walker·Devashibhai T. Adroja·Jun Zhao
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Abstract

We report neutron scattering measurements of the spinel oxide LiGaCr$_{4}$O$_{8}$, in which magnetic ions Cr$^{3+}$ form a breathing pyrochlore lattice. Our experiments reveal the coexistence of a nearly dispersionless resonance mode and dispersive spin wave excitations in the magnetically ordered state, which can be quantitatively described by a quantum spin model of hexagonal loops and linear spin wave theory with the same set of exchange parameters, respectively. Comparison to other Cr spinel oxides reveals a linear relationship between the resonance energy and lattice constant across all these materials, which is in agreement with our hexagonal loop calculations. Our results suggest a unified picture for spin resonances in Cr spinel oxides.

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Zheng He, Yiqing Gu, Hongliang Wo, Yu Feng, Die Hu, Yiqing Hao, Yimeng Gu, Helen C. Walker, Devashibhai T. Adroja, Jun Zhao. 2021-12-22. Neutron Scattering Studies of the Breathing Pyrochlore Antiferromagnet LiGaCr$_{4}$O$_{8}$. https://doi.org/10.1103/physrevlett.127.147205

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