论文标题
$ e_u^1 $ hifrared-Active声子模式的异常行为在bi $ _ {2-x} $ sr $ _x $ se $ _3 $ crystal
Anomalous behavior of the $E_u^1$ infrared-active phonon mode in a Bi$_{2-x}$Sr$_x$Se$_3$ crystal
论文作者
论文摘要
我们研究了拓扑绝缘子BI $ _ {2-x} $ sr $ _x $ _x $ se $ _3 $的$ e_u^1 $声子线的光谱演变。与拉曼活跃的声子不同，$ e_u^1 $模式在冷却晶体时表现出软化，相应的光谱线在温度下以$ t \ lyssim100 $ k的形式获得了明显的fano状形状。我们将后者的效果解释为Bulk Active Instrared Active Phonons over Active Phonons的特定辅助效果，以表面表面发出表面发出的dirac Dirac Electron。使用$ e_u^1 $模式的连贯的谐振激发作为表面敏感工具，我们已经检测到跨斜纹掺杂时散装$ e_u^1 $ phonon模式的表面对应物的软化。该观察结果可以证明在BI $ _ {2-x} $ sr $ _x $ se $ _3 $ Crystal的表面上增强了电子波相互作用。
We have studied spectral evolution of the $E_u^1$ phonon line of a topological insulator Bi$_{2-x}$Sr$_x$Se$_3$ with temperature. Unlike the Raman-active phonons, the $E_u^1$ mode demonstrates softening upon cooling the crystal, and the corresponding spectral line acquires a pronounced Fano-like shape at temperatures $T\lesssim100$ K. We interpret the latter effect as a signature of specific coupling of the bulk infrared active phonons to surface Dirac electrons. Using coherent resonant excitation of the $E_u^1$ mode as a surface sensitive tool, we have detected softening of the surface counterpart of the bulk $E_u^1$ phonon mode upon strontium doping. This observation can be an evidence of enhanced electron-phonon interaction at the surface of the Bi$_{2-x}$Sr$_x$Se$_3$ crystal.
