Evidence for magnon-phonon coupling in the topological magnet Cu3TeO6
Evidence for magnon-phonon coupling in the topological magnet Cu3TeO6
复制标题
拓扑磁体 Cu3TeO6 中磁子-声子耦合的证据
DOI：
10.1103/physrevb.101.214419
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发表时间：
2020-06-11
影响因子：
3.7
通讯作者：
Wen, Jinsheng
中科院分区：
文献类型：
--
作者：
Bao, Song;Cai, Zhengwei;Wen, Jinsheng
We perform thermodynamic and inelastic neutron scattering (INS) measurements to study the lattice dynamics (phonons) of a cubic collinear antiferromagnet ${\mathrm{Cu}}_{3}{\mathrm{TeO}}_{6}$ which hosts topological spin excitations (magnons). While the specific heat and thermal conductivity results show that the thermal transport is dominated by phonons, the deviation of the thermal conductivity from a pure phononic model indicates that there is a strong coupling between magnons and phonons. In the INS measurements, we find a mode in the excitation spectra at 4.5 K, which exhibits a slight downward dispersion around the Brillouin zone center. This mode disappears above the N\'eel temperature and thus cannot be a phonon. Furthermore, the dispersion is distinct from that of a magnon. Instead, it can be explained by the magnon-polaron mode, collective excitations resulting from the hybridization between magnons and phonons. We consider the suppression of the thermal conductivity and emergence of the magnon-polaron mode to be evidence for magnon-phonon coupling in ${\mathrm{Cu}}_{3}{\mathrm{TeO}}_{6}$.
We perform thermodynamic and inelastic neutron scattering (INS) measurements to study the lattice dynamics (phonons) of a cubic collinear antiferromagnet ${\mathrm{Cu}}_{3}{\mathrm{TeO}}_{6}$ which hosts topological spin excitations (magnons). While the specific heat and thermal conductivity results show that the thermal transport is dominated by phonons, the deviation of the thermal conductivity from a pure phononic model indicates that there is a strong coupling between magnons and phonons. In the INS measurements, we find a mode in the excitation spectra at 4.5 K, which exhibits a slight downward dispersion around the Brillouin zone center. This mode disappears above the N\'eel temperature and thus cannot be a phonon. Furthermore, the dispersion is distinct from that of a magnon. Instead, it can be explained by the magnon-polaron mode, collective excitations resulting from the hybridization between magnons and phonons. We consider the suppression of the thermal conductivity and emergence of the magnon-polaron mode to be evidence for magnon-phonon coupling in ${\mathrm{Cu}}_{3}{\mathrm{TeO}}_{6}$.