Observation of Screening in the Magneto-Coulomb Drag between Coupled Two-Dimensional Electron Systems

The coupling between two spatially separated two-dimensional electron gases is studied as a function of magnetic field B. We find oscillations in the transresistivity RT, which are up to 2 orders of magnitude enhanced compared to the B0ex0ex=0ex0ex0 case. RT vanishes in the regime of a quantum Hall plateau and shows a twin-peaked structure in the inter-plateau regions. This observation is in good agreement with a recent theory by M. C. B{}nsager et al. [Phys. Rev. Lett. 77, 1366 (1996)] who predicted a similar behavior caused by the interplay of screening and Landau quantization.