论文标题
栅极定义的量子点接触的静电电势形状
Electrostatic potential shape of gate defined quantum point contacts
论文作者
论文摘要
量子点接触（QPC）是纳米电路电路的基本构建块。对于它们的发射动力学以及相互作用的效果，例如0.7-Anomaly，静电电位的细节很重要，但是精确的电位形状通常是未知的。在这里，我们测量了各种QPC的一维子带间距，这是它们的电导的函数，并将我们的发现与侧向抛物线与硬壁限制的模型进行了比较。我们发现，附近的栅极定义的QPC与抛物线鞍点方案兼容。但是，随着人口稠密的子带的数量增加，库仑筛选会使潜在的底部变平，并且在有限的硬壁电势方面的描述变得更加现实。
Quantum point contacts (QPC) are fundamental building blocks of nanoelectronic circuits. For their emission dynamics as well as for interaction effects such as the 0.7-anomaly the details of the electrostatic potential are important, but the precise potential shapes are usually unknown. Here, we measure the one-dimensional subband spacings of various QPCs as a function of their conductance and compare our findings with models of lateral parabolic versus hard wall confinement. We find that a gate-defined QPC near pinch-off is compatible with the parabolic saddle point scenario. However, as the number of populated subbands is increased Coulomb screening flattens the potential bottom and a description in terms of a finite hard wall potential becomes more realistic.
