Quantized conductance in an AlAs two-dimensional electron system quantum point contact

被引：65

作者：

Gunawan, O. ^{[1
]}

Habib, B. ^{[1
]}

De Poortere, E. P. ^{[1
]}

Shayegan, M. ^{[1
]}

机构：

[1] Princeton Univ, Dept Elect Engn, Princeton, NJ 08544 USA

来源：

PHYSICAL REVIEW B | 2006年 / 74卷 / 15期

关键词：

D O I：

10.1103/PhysRevB.74.155436

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

We report experimental results on a quantum point contact (QPC) device formed in a wide AlAs quantum well where the two-dimensional electrons occupy two in-plane valleys with elliptical Fermi contours. To probe the closely-spaced, one-dimensional electric subbands, we fabricated a point contact device defined by shallow etching and a top gate that covers the entire device. The conductance versus top gate bias trace shows a series of weak plateaus at integer multiples of 2e(2)/h, indicating a broken valley degeneracy in the QPC and implying the potential use of QPC as a simple "valley filter" device. A model is presented to describe the quantized energy levels and the role of the in-plane valleys in the transport. We also observe a well-developed conductance plateau near 0.7x2e(2)/h which may reflect the strong electron-electron interaction in the system.

引用

页数：8

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