论文标题
电子分散，相关性和堆叠在1T-TAS $ _2 $的光激发状态
Electronic dispersion, correlations and stacking in the photoexcited state of 1T-TaS$_2$
论文作者
论文摘要
在这里，我们在1T-TAS $ _2 $的相称的电荷密度波（CDW）相位上执行角度和时间分辨的光电子光谱。采用具有不同探针脉冲极化的数据来映射化学势以下和高于化学势的电子状态的分散。光激发后，CDW顺序的波动擦除了靠近化学势的带分散，并将电荷间隙尺寸减半。该瞬态相设置在相干晶格运动的半个时期内，并受到强电子相关性的青睐。将实验结果与密度功能理论（DFT）计算进行比较，并对库仑排斥的评估进行了评估。我们的模拟表明，库仑排斥的筛选取决于tas $ _2 $层的堆叠顺序。这种自由度的纠缠表明，结构秩序和电子排斥都通过光诱导的CDW波动局部修改。
Here we perform angle and time-resolved photoelectron spectroscopy on the commensurate Charge Density Wave (CDW) phase of 1T-TaS$_2$. Data with different probe pulse polarization are employed to map the dispersion of electronic states below and above the chemical potential. Upon photoexcitation, the fluctuations of CDW order erase the band dispersion near to the chemical potential and halve the charge gap size. This transient phase sets within half a period of the coherent lattice motion and is favored by strong electronic correlations. The experimental results are compared to Density-Functional Theory (DFT) calculations with a self-consistent evaluation of the Coulomb repulsion. Our simulations indicate that the screening of Coulomb repulsion depends on the stacking order of the TaS$_2$ layers. The entanglement of such degrees of freedom suggest that both the structural order and electronic repulsion are locally modified by the photoinduced CDW fluctuations.
