Institute of Physics, Polish Academy of Sciences, Al Lotnikow 32/46, 02-668 Warsaw, Poland.
Phys Rev Lett. 2012 Dec 14;109(24):247604. doi: 10.1103/PhysRevLett.109.247604. Epub 2012 Dec 10.
X-band microwave spectroscopy is applied to study the cyclotron resonance in Bi(2)Te(3) exposed to ambient conditions. With its help, intraband transitions between Landau levels of relativistic fermions are observed. The Fermi velocity equals to 3260 m/s, which is much lower than has been reported in the literature for samples cleaved in vacuum. Simultaneous observation of bulk Shubnikov-de Haas oscillations by contactless microwave spectroscopy allows determination of the Fermi-level position. Occupation of topological surface states depends not only on bulk Fermi level but also on the surface band bending.
X 波段微波光谱学被应用于研究暴露在环境条件下的 Bi(2)Te(3)中的回旋共振。借助它，可以观察到相对论费米子的朗道能级之间的带内跃迁。费米速度等于 3260 m/s，这远低于在真空中劈开的样品在文献中的报道。通过非接触式微波光谱学同时观察到体舒布尼科夫-德哈斯振荡，从而可以确定费米能级的位置。拓扑表面态的占据不仅取决于体费米能级，还取决于表面能带弯曲。
