Observation of Magnon Polarons in a Uniaxial Antiferromagnetic Insulator
Observation of Magnon Polarons in a Uniaxial Antiferromagnetic Insulator
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DOI：
10.1103/physrevlett.125.217201
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发表时间：
2020-11-17
影响因子：
8.6
通讯作者：
Shi, Jing
中科院分区：
文献类型：
--
作者：
Li, Junxue;Simensen, Haakon T.;Shi, Jing
磁振子是磁子和声子混合激发的一种形式，首次在钇铁石榴石中被报道为自旋Seebeck效应响应的反常。在这里，我们报道了在单轴AFM绝缘体Cr2O_3中观察到的反铁磁(AFM)磁振子。尽管磁振子的能量比声学声子的能量高，但在类似于6T的自旋-翻转相变附近，左撇子的磁振子谱向下移动，与声学声子杂化形成AFM磁振子极化子，这也可以用自旋Seebeck效应来探测。在低温下，由于磁振子的作用，自旋Seebeck信号被增强。
Magnon polarons, a type of hybridized excitations between magnons and phonons, were first reported in yttrium iron garnet as anomalies in the spin Seebeck effect responses. Here, we report an observation of antiferromagnetic (AFM) magnon polarons in a uniaxial AFM insulator Cr2O3. Despite the relatively higher energy of magnon than that of the acoustic phonons, near the spin-flop transition of similar to 6 T, the lefthanded magnon spectrum shifts downward to hybridize with the acoustic phonons to form AFM magnon polarons, which can also be probed by the spin Seebeck effect. The spin Seebeck signal is founded to be enhanced due to the magnon polarons at low temperatures.