论文标题
磁性拓扑绝缘子的光学响应的演变Mn（Bi $ _ {1-x} $ SB $ _ {X} $）$ _ 2 $ _ 2 $ TE $ _4 $带有SB内容
Evolution of the optical response of the magnetic topological insulators Mn(Bi$_{1-x}$Sb$_{x}$)$_2$Te$_4$ with Sb content
论文作者
论文摘要
MNBI $ _2 $ te $ _4 $是内在的抗铁磁拓扑绝缘子的有前途的代表，它可以启用稀有的量子机械效应，例如量子异常效果。特别是在低温下，已经报道了许多研究，证明了该化合物在$ t _ {\ mathrm {n}} $下方的磁性状态下的巨大潜力。在最近的发现中，合金化合物MN（Bi $ _ {1-x} $ sb $ _x $）$ _ 2 $ te $ _4 $被认为是实现理想的Weyl Semirimetal状态的有趣候选人。通过通过SB交换BI，电子结构受Fermi能量的转移而影响，并且已经预测了能量差距的减少。在这项工作中，我们调查并比较Mn（Bi $ _ {1-X} $ SB $ _X $）$ _ 2 $ TE $ _4 $单晶具有各种SB掺杂级别$ X $由红外反射率测量的单晶。我们观察到SB含量对表征样品金属状态的低能激发的影响很大。不同的$ x $ = 0.26晶体在其光学响应方面显示出显着差异，也具有强大的位置依赖性。将发现与最近报道的纯化合物MNBI $ _2 $ te $ _4 $的最近报道的光电频谱进行了比较。
MnBi$_2$Te$_4$ is a promising representative of intrinsic antiferromagnetic topological insulators, which could enable rare quantum mechanical effects like the quantum anomalous Hall effect. Especially at low temperatures, numerous studies have been reported, demonstrating the great potential of this compound in the magnetically ordered state below $T_{\mathrm{N}}$. Among recent findings, the alloy compound Mn(Bi$_{1-x}$Sb$_x$)$_2$Te$_4$ has been suggested to be an interesting candidate for the realization of an ideal Weyl semimetal state. By exchanging Bi by Sb, the electronic structure is influenced in terms of a shift of the Fermi energy, and a decrease in the energy gap has been predicted. In this work, we investigate and compare the optical conductivity of Mn(Bi$_{1-x}$Sb$_x$)$_2$Te$_4$ single crystals with various Sb doping levels $x$ by infrared reflectivity measurements. We observe a big impact of the Sb content on the low-energy excitations characterizing the metallic state of our samples. Different $x$=0.26 crystals show significant differences in their optical response and also a strong position dependence. The findings are compared to the recently reported optical conductivity spectrum of the pure compound MnBi$_2$Te$_4$.
