Skip to content

Negative Electron-electron Drag Between Narrow Quantum Hall Channels

H. C. W. Tso, D. J. W. Geldart, P. Vasilopoulos

cond-mat.mes-hallarXiv:cond-mat/9711144

Abstract

Momentum transfer due to Coulomb interaction between two parallel, two-dimensional, narrow, and spatially separated layers, when a current Idrive is driven through one layer, is studied in the presence of a perpendicular magnetic field B. The current induced in the drag layer, Idrag, is evaluated self-consistently with Idrive as a parameter. Idrag can be positive or negative depending on the value of the filling factor νof the highest occupied bulk Landau level (LL). For a fully occupied LL, Idrag is negative, i.e., it flows opposite to Idrive, whereas it is positive for a half-filled LL. When the circuit is opened in the drag layer, a voltage ΔVdrag develops in it; it is negative for a half-filled LL and positive for a fully occupied LL. This positive ΔVdrag, expressing a negative Coulomb drag, results from energetically favored near-edge inter-LL transitions that occur when the highest occupied bulk LL and the LL just above it become degenerate.

Create a lesson