论文标题
从高阳性扫描隧道光谱中获得状态的局部密度的归一化过程
Normalization procedure for obtaining the local density of states from high-bias scanning tunneling spectroscopy
论文作者
论文摘要
在高偏置状态下进行的差分电导光谱（在其中应用电压超过样品工作函数）是由于变化的隧道屏障的影响，是对状态局部密度的量度差。此外，大型施加电压通常会使恒定的高度测量在实验上不切实际，持续恒定光谱范围是有利的边缘。但是，由于尖端高度的变化，这种情况下的差分电导甚至从状态的局部密度进一步删除。在这里，我们提出了一种归一化方案，用于从以恒定或恒定高模式获得的高偏置扫描隧道光谱中提取状态的局部密度。我们扩展了此模型，以说明探测状态的平面动量对整体电流的影响。我们通过将其应用于侧向限制的场发射共振来证明拟议方案的有效性，后者以峰形的光谱特征显示具有明确的平面内动量。
Differential conductance spectroscopy performed in the high bias regime -- in which the applied voltage exceeds the sample work function -- is a poor measure of the local density of states due to the effects of the changing tunnel barrier. Additionally, the large applied voltage oftentimes makes constant-height measurement experimentally impractical, lending constant-current spectroscopy an advantageous edge; but the differential conductance in that case is even further removed from the local density of states due to the changing tip height. Here, we present a normalization scheme for extracting the local density of states from high bias scanning tunneling spectroscopy, obtained in either constant-current or constant-height mode. We extend this model to account for the effects of the in-plane momentum of the probed states to the overall current. We demonstrate the validity of the proposed scheme by applying it to laterally confined field-emission resonances, which appear as peak-shaped spectroscopic features with a well-defined in-plane momentum.
