Imaging disorder-induced scattering centers in quantum Hall incompressible strip

While the disorder-induced quantum Hall (QH) effect has been studied previously, the effect ofdisorder potential on microscopic features of the integer QH effect remains unclear, particularly forthe incompressible (IC) strip. In this research, a scanning gate microscope incorporated with thenonequilibrium transport technique is used to image the region of QH IC strip that emerges near thesample edge. It was found that different mobility samples with varying disorder potentials showedthe same spatial dependence of the IC strip on the filling factor ({\nu}). In the low-mobility samplealone, scattering centers such, bright, dark and annular patterns, alternately appear within the IC strip. These observed patterns are ascribed to inter-LL scattering assisted by resonance tunnelingthrough an impurity bound state. It is concluded that disorder-induced scattering can be effectivelydetected using the applied technique in a low-mobility sample.

PDF Abstract