论文标题
使用电子干涉法对尖端诱导的电势的准确表征
Accurate characterization of tip-induced potential using electron interferometry
论文作者
论文摘要
前提是众所周知，使用扫描探针显微镜作为局部静电门，可以访问纳米级的真实空间信息以及纳米级的电荷传输。在这里，我们专注于尖端电位的准确表征，在尖端局部耗尽二维电子气体（2DEG）的状态下，托管在半导体异质结构中。在2维eg中定义的量子点接触的附近扫描尖端，我们观察到在设备电导的地图中低温下的Fabry-Pérot干扰条纹。我们用尖端电压利用这些条纹的演变来测量电子干涉仪的耗尽半径的变化。我们发现，考虑到尖端的圆锥形形状的半古典有限元元素自一致模型与实验数据达到了忠实的对应关系。
Using the tip of a scanning probe microscope as a local electrostatic gate gives access to real space information on electrostatics as well as charge transport at the nanoscale, provided that the tip-induced electrostatic potential is well known. Here, we focus on the accurate characterization of the tip potential, in a regime where the tip locally depletes a two-dimensional electron gas (2DEG) hosted in a semiconductor heterostructure. Scanning the tip in the vicinity of a quantum point contact defined in the 2DEG, we observe Fabry-Pérot interference fringes at low temperature in maps of the device conductance. We exploit the evolution of these fringes with the tip voltage to measure the change in depletion radius by electron interferometry. We find that a semi-classical finite-element self-consistent model taking into account the conical shape of the tip reaches a faithful correspondence with the experimental data.
