Department of Electrical Engineering, Princeton University, Princeton, New Jersey 08544, USA.
Phys Rev Lett. 2012 Jul 20;109(3):036801. doi: 10.1103/PhysRevLett.109.036801. Epub 2012 Jul 17.
Measurements on very low disorder two-dimensional electrons confined to relatively wide GaAs quantum well samples with tunable density reveal a close competition between the electron liquid and solid phases near the Landau level filling factor ν=1. As the density is raised, the fractional quantum Hall liquid at ν=4/5 suddenly disappears at a well-width dependent critical density, and then reappears at higher densities with insulating phases on its flanks. These insulating phases exhibit reentrant ν=1 integer quantum Hall effects and signal the formation of electron Wigner crystal states. Qualitatively similar phenomena are seen near ν=6/5.
对非常低无序的二维电子在可调密度的相对宽 GaAs 量子阱样品中的测量表明，在朗道能级填充因子 ν=1 附近，电子液相和固相之间存在着激烈竞争。随着密度的增加，分数量子霍尔液在 ν=4/5 处突然在一个依赖于阱宽的临界密度处消失，然后在更高的密度处再次出现，其边缘带有绝缘相。这些绝缘相表现出再入 ν=1 整数量子霍尔效应，并表明电子维格纳晶体状态的形成。在 ν=6/5 附近也观察到了类似的定性现象。
