发表机构
University of Tsukuba（筑波大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文通过泵浦-探测光谱研究TiSe$_2$电荷密度波态，发现非振荡信号在1.5 eV处符号反转，归因于带间跃迁红移，且光学声子与CDW模式的光谱依赖性差异表明模式选择性电子-声子耦合。
AI 中文摘要
我们报道了在氦温度下对TiSe$_2$电荷密度波（CDW）态进行的时间和光谱分辨的泵浦-探测光谱测量。光谱分辨信号的非振荡分量在1.5 eV附近表现出符号反转，这被解释为源于Se $p$基价带与Ti $d$衍生导带之间带间跃迁的光学跃迁能量的红移。此外，振荡分量在光学声子和CDW衍生模式之间表现出明显的光谱依赖性，表明存在模式选择性耦合。
英文摘要
We report on time- and spectrally resolved pump-probe spectroscopy measurement on the charge-density wave (CDW) state of TiSe$_2$ at helium temperatures. The non-oscillatory component of the spectrally resolved signals exhibit a sign reversal near 1.5 eV, which was interpreted as a redshift of the optical transition energy originated from the interband transition between the Se $p$-based valence band to the Ti $d$-derived conduction band. Furthermore, the oscillatory components exhibit distinct spectral dependences between the optical phonons and the CDW-derived modes, suggesting the mode-selective coupling.
