Hatke A T, Deng H, Liu Yang, Engel L W, Pfeiffer L N, West K W, Baldwin K W, Shayegan M
National High Magnetic Field Laboratory, Tallahassee, FL 32310, USA.
Department of Electrical Engineering, Princeton University, Princeton, NJ 08544, USA.
Sci Adv. 2019 Mar 15;5(3):eaao2848. doi: 10.1126/sciadv.aao2848. eCollection 2019 Mar.
We studied a bilayer system hosting two-dimensional electron systems (2DESs) in close proximity but isolated from one another by a thin barrier. One 2DES has low electron density and forms a Wigner solid (WS) at high magnetic fields. The other has much higher density and, in the same field, exhibits fractional quantum Hall states (FQHSs). The WS spectrum has resonances which are understood as pinning modes, oscillations of the WS within the residual disorder. We found the pinning mode frequencies of the WS are strongly affected by the FQHSs in the nearby layer. Analysis of the spectra indicates that the majority layer screens like a dielectric medium even when its Landau filling is ~/, at which the layer is essentially a composite fermion (CF) metal. Although the majority layer is only ~ one WS lattice constant away, a WS site only induces an image charge of ~0.1e in the CF metal.
我们研究了一种双层系统，其中包含两个二维电子系统（2DES），它们彼此靠得很近，但被一个薄势垒隔开。一个2DES具有低电子密度，并在高磁场下形成维格纳固体（WS）。另一个具有高得多的密度，并且在相同磁场下表现出分数量子霍尔态（FQHS）。WS光谱具有共振，这些共振被理解为钉扎模式，即WS在残余无序中的振荡。我们发现WS的钉扎模式频率受到附近层中FQHS的强烈影响。光谱分析表明，即使多数层的朗道填充数约为~ / ，该层本质上是复合费米子（CF）金属时，多数层也像电介质一样屏蔽。尽管多数层仅距一个WS晶格常数左右，但一个WS位点在CF金属中仅诱导出约0.1e的镜像电荷。
