Hatke A T, Liu Yang, Magill B A, Moon B H, Engel L W, Shayegan M, Pfeiffer L N, West K W, Baldwin K W
National High Magnetic Field Laboratory, Tallahassee, Florida 32310, USA.
Department of Electrical Engineering, Princeton University, Princeton, New Jersey 08544, USA.
Nat Commun. 2014 Jun 20;5:4154. doi: 10.1038/ncomms5154.
In high magnetic fields, two-dimensional electron systems can form a number of phases in which interelectron repulsion plays the central role, since the kinetic energy is frozen out by Landau quantization. These phases include the well-known liquids of the fractional quantum Hall effect, as well as solid phases with broken spatial symmetry and crystalline order. Solids can occur at the low Landau-filling termination of the fractional quantum Hall effect series but also within integer quantum Hall effects. Here we present microwave spectroscopy studies of wide quantum wells that clearly reveal two distinct solid phases, hidden within what in d.c. transport would be the zero diagonal conductivity of an integer quantum-Hall-effect state. Explanation of these solids is not possible with the simple picture of a Wigner solid of ordinary (quasi) electrons or holes.
在强磁场中，二维电子系统可以形成许多相，其中电子间的排斥作用起着核心作用，因为动能被朗道量子化冻结。这些相包括分数量子霍尔效应中著名的液体相，以及具有破缺空间对称性和晶体序的固相。固相可以出现在分数量子霍尔效应序列的低朗道填充端，但也可以出现在整数量子霍尔效应中。在这里，我们展示了对宽量子阱的微波光谱研究，这些研究清楚地揭示了两个不同的固相，它们隐藏在直流输运中整数量子霍尔效应态的零对角电导率区域内。用普通（准）电子或空穴的维格纳固体的简单图像无法解释这些固相。
