Observation of Quantized Hall Drag in a Strongly Correlated Bilayer Electron System

Abstract

The frictional drag between parallel two-dimensional electron systems has been measured in a regime of strong interlayer correlations. When the bilayer system enters the excitonic quantized Hall state at total Landau level filling factor [Formula presented], the longitudinal component of the drag vanishes but a strong Hall component develops. The Hall drag resistance is observed to be accurately quantized at [Formula presented]. © 2002 The American Physical Society.