  The electron-electron interaction quantum correction to the conductivity of
the gated double well Al$_x$Ga$_{1-x}$As/GaAs structures is investigated
experimentally. The analysis of the temperature and magnetic field dependences
of the conductivity tensor allows us to obtain reliably the diffusion part of
the interaction correction for the regimes when the structure is balanced and
when only one quantum well is occupied. The surprising result is that the
interaction correction does not reveal resonant behavior; it is practically the
same for both regimes.
