Spin effects in the magnetodrag between double quantum wells - art. no. 041305

We report on the selectivity to spin in a drag measurement. This selectivit y to spin causes deep minima in the magnetodrag at odd filling factors for matched electron densities at magnetic fields and temperatures at which the hare spin energy is only one tenth of the temperature. For mismatched dens ities the selectivity causes a 1/B periodic oscillation, such that negative minima in the drag are observed whenever the majority spins at the Fermi e nergies of the two-dimensional electron gases are antiparallel, and positiv e maxims whenever the majority spins at the Fermi energies are parallel.