Interaction-induced merging of Landau levels in an electron system of double quantum wells.

We show that the disappearance of the chemical potential jumps over the range of perpendicular magnetic fields at fixed integer filling factor in a double quantum well with a tunnel barrier is caused by the interactioninduced level merging. The distribution function in the merging regime is special in that the probability to find an electron with energy equal to the chemical potential is different for the two merged levels. [ABSTRACT FROM AUTHOR]