论文标题
时间和角度分辨光光谱揭示的对列内电子状态的异常贡献
Anomalous contribution to the nematic electronic states from the structural transition in FeSe revealed by time- and angle-resolved photoemission spectroscopy
论文作者
论文摘要
在FESE超导体上进行了高分辨率的时间和角度分辨光发射测量。使用超快的光激发，仅在我们的时间和能量分辨率的Brillouin-Zone中心附近的$ d_ {Yz} $ - 轨道衍生的频段中发现了两个对应于两个超快电子相变的关键激发通量。在与详细的温度依赖测量值进行比较后，我们得出结论，在超导转变温度上方有两个平衡电子相变（约为90 k和120 K），并且从结构升级中对10 MEV的尺度上的尺度上有一个异常贡献。我们的观察结果强烈表明，必须在FESE的能量带的发展中考虑到120 K处的电子相变，此外，结构过渡的贡献在基于铁的铁基高温超导体的列相中起着重要作用。
High-resolution time- and angle-resolved photoemission measurements were made on FeSe superconductors. With ultrafast photoexcitation, two critical excitation fluences that correspond to two ultrafast electronic phase transitions were found only in the $d_{yz}$-orbit-derived band near the Brillouin-zone center within our time and energy resolution. Upon comparison to the detailed temperature dependent measurements, we conclude that there are two equilibrium electronic phase transitions (at approximately 90 and 120 K) above the superconducting transition temperature, and an anomalous contribution on the scale of 10 meV to the nematic states from the structural transition is experimentally determined. Our observations strongly suggest that the electronic phase transition at 120 K must be taken into account in the energy band development of FeSe, and, furthermore, the contribution of the structural transition plays an important role in the nematic phase of iron-based high-temperature superconductors.
