Low-temperature anomalies in magneto-drag at higher Landau levels

摘要

We have studied the temperature dependence of frictional drag in the integer quantum Hall regime for both matched and mismatched densities. The crossover from the high-S and high-71 regime where the drag decreases with decreasing temperature to the low-S and low-T regime where the drag anomalously increases with decreasing tempeature reveals the existence of two different mechanisms producing the drag. In the low-S and ow-T regime, the positive drag for matched densities is caused by the same mechanism as that for the negative drag for mismatched densities.