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arXiv 2104.02510cond-mat.str-elcond-mat.mtrl-sci
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磁性拓扑绝缘体EuIn PDMATHAAB As $_{2}$中电荷、自旋和晶格激发相互作用的红外研究

Infrared study of the interplay of charge, spin, and lattice excitations in the magnetic topological insulator EuIn$_2$As$_{2}$

B. Xu, P. Marsik, S. Sarkar, F. Lyzwa, Y. Zhang, B. Shen, C. Bernhard

摘要:

我们报告的红外光谱研究的轴子拓扑绝缘体候选人EuIn $_2$作为$_2$的Eu矩表现出A型反铁磁(AFM)低于$T_N \simeq 18 \mathrm{K}$秩序。低能响应由原点处的弱Drude峰、185 cm $^{-1}$处的显著红外激活声子模和600 cm $^{-1}$附近的自由载流子等离子体边缘组成。带间跃迁开始于800 cm $^{-1}$以上,在5\,000和12\,000 cm $^{-1}$处产生一系列弱吸收带,在20\,000、27\,500和32\,000 cm $^{-1}$处产生强吸收带.原子力显微镜的转变引起了明显的异常的电荷响应,在$T_N$周围的自由载流子散射率的尖点样的最大值和大的磁分裂的带间跃迁在5\,000和12\,000 cm $^{-1}$。在185 cm $^{-1}$处的声子模在$T_N$附近也具有反常的温度依赖性,这表明它与Eu自旋的涨落耦合。结合的数据提供的证据之间的电荷,自旋和晶格自由度的强相互作用。

英文摘要:

We report an infrared spectroscopy study of the axion topological insulator candidate EuIn$_2$As$_2$ for which the Eu moments exhibit an A-type antiferromagnetic (AFM) order below $T_N \simeq 18 \mathrm{K}$. The low energy response is composed of a weak Drude peak at the origin, a pronounced infrared-active phonon mode at 185 cm$^{-1}$ and a free carrier plasma edge around 600 cm$^{-1}$. The interband transitions start above 800 cm$^{-1}$ and give rise to a series of weak absorption bands at 5\,000 and 12\,000 cm$^{-1}$ and strong ones at 20\,000, 27\,500 and 32\,000 cm$^{-1}$. The AFM transition gives rise to pronounced anomalies of the charge response in terms of a cusp-like maximum of the free carrier scattering rate around $T_N$ and large magnetic splittings of the interband transitions at 5\,000 and 12\,000 cm$^{-1}$. The phonon mode at 185 cm$^{-1}$ has also an anomalous temperature dependence around $T_N$ which suggests that it couples to the fluctuations of the Eu spins. The combined data provide evidence for a strong interaction amongst the charge, spin and lattice degrees of freedom.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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