Hysteresis in the Magneto-Transport of Layered 2D Electron Systems
16 March 1987
In layered two-dimensional electron systems of modulation doped multiquantum wells we have observed considerable hysteresis in the magneto-transport coefficients Pxx and Pxy as the magnetic field is varied in opposing directions. In samples with small interlayer density variations, the hysteresis is most pronounced in the field regime of the quantized Hall effect. Samples with intentionally strong interlayer density variations show giant completely reproducible instabilities, assuming the characteristics of hysteretic switching. None of these phenomena has ever been observed in single 2D systems. While the origin of switching and hysteresis remain unclear, we speculate that the instabilities arise from QHE-induced vanishing in-plane conductivity combined with capacitive coupling between neighboring layers. Our observation calls in question the generally assumed equivalence of multilayer and single layer 2D systems.