Abstract
In this paper, we review low temperature electronic transport results in high quality two-dimensional electron systems. We discuss the quantization of the diagonal resistance, Rx x, at the edges of several quantum Hall states. Each quantized Rx x value turns out to be close to the difference between the two adjacent Hall plateaus in the off-diagonal resistance, Rx y. Moreover, peaks in Rx x occur at different positions in positive and negative magnetic fields. All three Rx x features can be explained quantitatively by a ∼1% cm electron density gradient. Furthermore, based on this observation, the well known but still enigmatic resistivity rule, relating Rx x to d Rx y / d B, finds a simple interpretation in terms of this gradient. In another sample, at 1.2 K, Rx x we observe a strongly linear magnetic field dependence. Surprisingly, this linear magnetoresistance also originates from the density gradient. Our findings throw an unexpected light on the relationship between the experimentally measured Rx x and the diagonal resistivity ρx x.
Original language | English (US) |
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Pages (from-to) | 88-93 |
Number of pages | 6 |
Journal | Solid State Communications |
Volume | 140 |
Issue number | 2 |
DOIs | |
State | Published - Oct 2006 |
Externally published | Yes |
All Science Journal Classification (ASJC) codes
- General Chemistry
- Condensed Matter Physics
- Materials Chemistry
Keywords
- D. Density gradient
- D. Linear magnetoresistance
- D. Quantum Hall effect
- D. Resistivity rule