  Two-mode squeezed states are scalable and robust entanglement resources for
continuous-variable and hybrid quantum information protocols at a distance. We
consider the effect of a linear cross talk in the multimode distribution of
two-mode squeezed states propagating through parallel similar channels. First,
to reduce degradation of the distributed Gaussian entanglement, we show that
the initial two-mode squeezing entering the channel should be optimized already
in the presence of a small cross talk. Second, we suggest simultaneous
optimization of relative phase between the modes and their linear coupling on a
receiver side prior to the use of entanglement, which can fully compensate the
cross talk once the channel transmittance is the same for all the modes. For
the realistic channels with similar transmittance values for either of the
modes, the cross talk can be still largely compensated. This method relying on
the mode interference overcomes an alternative method of entanglement
localization in one pair of modes using measurement on another pair and
feed-forward control. Our theoretical results pave the way to more efficient
use of multimode continuous-variable photonic entanglement in scalable quantum
networks with cross talk.
