论文标题
拓扑绝缘子中的金属掺杂 - 可调节的Terahertz的关键
Metal Doping in Topological Insulators- A Key for Tunable Generation of Terahertz
论文作者
论文摘要
独特的表面边缘状态使拓扑绝缘子成为不同应用之间的主要重点。在本文中，我们将大型尼伯（NB）掺杂的BI2SE3拓扑绝缘子（TI）的单晶体与公式NB0.25BI2SE3合成。单晶的特征是使用各种技术，例如粉末X射线衍射仪（PXRD），DC磁化测量，拉曼和超快瞬态吸收光谱（TRUS）。 PXRD中有（00L）反射，并且在FC和ZFC测量中，从2.5K处可见的透明型过渡可以明显看出超导的晶体。拉曼光谱法用于在样品中找到不同的振动模式。此外，样品被1.90 eV的泵激发，并考虑用于Terahertz分析的1.38 eV的动力学衰减曲线。差异衰减曲线具有不同的振动，这些振荡已通过Terahertz进行了分析。本文不仅提供了NB掺杂样本中Terahertz生成的证据以及未依存的样本，而且还表明了掺杂原子改变了电荷载体的动力学，从而改变了Terahertz频率响应的变化。总之，合适的掺杂剂可以用作Tiahertz频率可调性的处理器。
The unique surface edge states make topological insulators a primary focus among different applications. In this article, we synthesized a large single crystal of Niobium(Nb)-doped Bi2Se3 topological insulator (TI) with a formula Nb0.25Bi2Se3. The single crystal has characterized by using various techniques such as Powder X-ray Diffractometer (PXRD), DC magnetization measurements, Raman, and Ultrafast transient absorption spectroscopy (TRUS). There are (00l) reflections in the PXRD, and Superconductivity ingrown crystal is evident from clearly visible diamagnetic transition at 2.5K in both FC and ZFC measurements. The Raman spectroscopy is used to find the different vibrational modes in the sample. Further, the sample is excited by a pump of 1.90 eV, and a kinetic decay profile at 1.38 eV is considered for terahertz analysis. The differential decay profile has different vibrations, and these oscillations have analyzed in terms of terahertz. This article not only provides evidence of terahertz generation in Nb-doped sample along with undoped sample but also show that the dopant atom changes the dynamics of charge carriers and thereby the shift in the Terahertz frequency response. In conclusion, a suitable dopant can be used as a processor for the tunability of terahertz frequency in TI.
