论文标题
半金属1T-Tite2中准颗粒分散动力学的温度演变，通过高分辨率角度分辨光发射光谱和超快光泵探针光谱
Temperature evolution of quasiparticle dispersion dynamics in semimetallic 1T-TiTe2 via high-resolution angle-resolved photoemission spectroscopy and ultrafast optical pump-probe spectroscopy
论文作者
论文摘要
高分辨率角度分辨光发射光谱和超快光泵探针光谱法用于研究半金属1T-Tite2 Quasiparticle分散和动力学。检测到沿G-M方向具有相同能量尺度和温度依赖性行为的扭结和平坦带。两者都在低温下表现出来，但随着温度升高而模糊。扭结是由电子音波耦合形成的。局部平面频带可能与电子 - 音波耦合密切相关。超快速光谱鉴定在10-300 K范围内的多个不同的时间尺度。对最快的衰减过程的定量分析证明了高温下的寿命依赖性显着，而在发生异常的霍尔系数的情况下，这种寿命的变化在〜100 k以下的缓慢变化。在低温下，提取了频率约为4.36 THz的连贯的A1G声子模式。频温依赖性表明，随着温度下降，声子硬化发生，而肛门效应可以解释它。频率依赖性表明随着通量增加，声子变软。
High-resolution angle-resolved photoemission spectroscopy and ultrafast optical pump-probe spectroscopy were used to study semimetallic 1T - TiTe2 quasiparticle dispersion and dynamics. A kink and a flat band, having the same energy scale and temperature-dependent behaviors along the G-M direction, were detected. Both manifested at low temperatures but blurred as temperature increased. The kink was formed by an electron-phonon coupling. And the localized flat band might be closely related to an electron-phonon coupling. Ultrafast optical spectroscopy identified multiple distinct time scales in the 10-300 K range. Quantitative analysis of the fastest decay process evidenced a significant lifetime temperature dependence at high temperatures, while this starts to change slowly below ~ 100 K where an anomalous Hall coefficient occurred. At low temperature, a coherent A1g phonon mode with a frequency of ~ 4.36 THz was extracted. Frequency temperature dependence suggests that phonon hardening occurs as temperature falls and anharmonic effects can explain it. Frequency fluence dependence indicates that the phonons soften as fluence increases.
