Study of Tunneling Phenomena and Electron Correlation Effects on Transport in a Very Small Semiconductor

整数量子霍尔效应（QHE）和一维安德森局域化（AL）是一种更普遍的现象，定向局域化（DL），预测发生在无序的一维波导称为“量子铁路”（QRR）的限制特殊情况。我们已经调查了最近的测量结果康等。边缘的二维电子系统之间的电子转移，并确定在一般的QRR的第一个实验证据，但到现在为止完全理论，DL制度，统一的QHE和AL。我们已经开始澄清如何影响电子转移通过障碍。我们已经做了我们的计算机模拟使用递归绿色的功能技术。我们考虑系统与一个额外的光滑随机势模型的电子库仑相互作用与施主离子在掺杂层相邻的2DEG的。透射峰被发现是足够宽的解释所观察到的持久性的电导峰。这一结果与数据中没有自旋特征是一致的。为了进一步探索这一点，我们进行了自洽Hartree计算的边缘通道能量，治疗的无序的平均场近似的影响。我们计算的边缘沟道交叉预测的隧穿最大值的位置与观察到的微分电导峰的位置定量一致，我们还提出了一个简单的测量，应该能够解决明确的重要问题，自旋在这个系统中发挥的作用。

The integer quantum Hall effect (QHE) and one-dimensional Anderson localization (AL) are limiting special cases of a more general phenomenon, directed localization (DL), predicted to occur in disordered one-dimensional wave guides called "quantum railroads" (QRR). We have investigated the results of recent measurements by Kang et al. of electron transfer between edges of two-dimensional electron systems and identify the first experimental evidence of QRR's in the general, but until now entirely theoretical, DL regime that unifies the QHE and AL.We have begun by clarifying how disorder affects electron transfer through the barrier. We have done our computer simulations using a recursive Green's function technique. We consider the system with an additional smooth random potential that models the electron Coulomb interaction with donor ions in the doped layer adjacent to the 2DEG's. The transmission peak is found to be sufficiently broad to explain the observed persistence of the conductance peaks. This results are consistent with the absence of features of spin in the data. Temperature dependence of the peak structure is also explained.To explore this further we performed self-consistent Hartree calculations of the edge channel energies, treating the effects of disorder in a mean-field approximation. The locations of the tunneling maxima predicted by our calculations of the edge channel crossings are in quantitative agreement with the observed positions of the differential conductance peaks.We have also proposed a simple measurement that should be able to settle unambiguously important issue of the role that spin plays in this system.