Probing Quantum Hall State Homogeneity with Surface Waves

20th International Conference on the Application of High Magnetic Fields in Semiconductor Physics

Msall, M.E.^1,2 ; Dietsche, W.^2 ; Schmult, S.^2,3 ; Klitzing, K.Von.^2

Department of Physics and Astronomy, Bowdoin College, Brunswick, ME 04011, United States^1

Max-Planck-Institute for Solid State Research, Heisenbergstraße 1, D-70569 Stuttgart, Germany^2

Technical University Dresden, Noethnitzer Str. 64, D-01187 Dresden, Germany^3

关键词: Conducting filament;    Localized heating;    Low-frequency;    Quantum Hall state;    Simultaneous measurement;    Simultaneous reduction;    Single quantum well;    Vector network analyzers;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/456/1/012030/pdf
DOI  :  10.1088/1742-6596/456/1/012030

来源: IOP

【 摘 要 】

We study single quantum wells and matched density bilayer samples. Simultaneous measurements of the Hall voltages using low frequency lock-in techniques and of the changes in the 232 MHz (12.6 μm) SAW propagation measured with a vector network-analyzer allow comparison of the complex bulk and edge conductivities. The vtotal1 bilayer state is seen directly in the SAW measurement only when the conductivity is below ∼ 6 × 10-7Siemens and is destroyed at moderate SAW powers by localized heating. The simultaneous reduction of the conductivity minima extracted from Hall data and from SAW data conclusively demonstrates that the vtotal1 state disappears simultaneously throughout the bulk and not by the formation of competing domains or conducting filaments.