We study the Coulomb drag between two spatially separated electron systems in the quantum Hall regime. At a fixed temperature, the drag is peaked near the transitions between plateaus. The temperature dependence of the drag is a probe of the dynamics of the Hall system in a frequency and wave-vector regime inaccessible to transport measurements in a single layer. Most strikingly, in the transition regions it directly measures an exponent η, discussed by Chalker, that is characteristic of the fractal structure of the critical eigenstates.
All Science Journal Classification (ASJC) codes
- Condensed Matter Physics