Publications Details
Quantization and chiral edge state properties in nearly 3D quantum well structures
We report magneto-transport measurements including Hall, Rxy, longitudinal, Rxx, and vertical, Rzz, magnetoresistance on nearly 3-dimensional (3D) 200 layer GaAs/AlGaAs quantum well structures. Although the interlayer band-width is nearly 20% of the Fermi energy, we still observe complete quantization of the Hall resistance for the 3D quantum Hall state. The temperature dependence of the Rxx minimum shows two unusual features: initially, at higher temperatures 1 K where the quantum Hall state develops, a gap with an activation energy much smaller than the Landau gap is observed; in the low temperature limit 0.030 K a variable range hopping behavior takes over with a residual resistivity limit. Independent measurements of Gzz (in 3D ≈ 1/Rzz) where the chiral edge states dominate the vertical transport show the same temperature dependence. © 1998 Published by Elsevier Science B.V. All rights reserved.