Kumar N, Ishchenko D V, Milekhin I A, Yunin P A, Kyrova E D, Korsakov A V, Tereshchenko O E
Rzhanov Institute of Semiconductor Physics, SB RAS, Novosibirsk, 630090, Russia.
Tomsk State University, 36 Lenin Ave., Tomsk, 634050, Russia.
Phys Chem Chem Phys. 2024 Nov 27;26(46):29036-29047. doi: 10.1039/d4cp02994a.
Interaction of phonons with Dirac-like electronic states sets the fundamental limit of electron transport in topological insulators (TIs). Polarization-resolved and resonant Raman scattering of bulk and surface electronic excitation and vibrational modes in BiTe and BiSbTeSe (BSTS) thin films was investigated. At photon energies () of 1.57 and 2.54 eV, A11g and A21g (LO) modes in BiTe and BSTS were resonantly excited owing to interband optical excitations of the surface Dirac state (DS) and bulk conduction band (CB), respectively. At room temperature, the resonance of the surface phonon of Raman and IR active modes E1u (LO) and A11u (LO) was observed in BiTe because of interband excitation of bulk CB, and interband transition of DS resonantly excited the A21u (LO) surface phonon in BSTS. A Fano line-shape suggested interference in the presence of electron-phonon coupling of the surface states.
声子与类狄拉克电子态的相互作用设定了拓扑绝缘体（TI）中电子输运的基本极限。研究了BiTe和BiSbTeSe（BSTS）薄膜中体电子激发和表面电子激发以及振动模式的偏振分辨共振拉曼散射。在光子能量为1.57和2.54 eV时，BiTe和BSTS中的A11g和A21g（LO）模式分别由于表面狄拉克态（DS）和体导带（CB）的带间光激发而被共振激发。在室温下，由于体CB的带间激发，在BiTe中观察到拉曼和红外活性模式E1u（LO）和A11u（LO）的表面声子共振，并且DS的带间跃迁共振激发了BSTS中的A21u（LO）表面声子。费诺线形表明在表面态的电子 - 声子耦合存在时发生了干涉。
