Compensating the Cross-Talk in Two-Mode Continuous-Variable Quantum Communication

We address distribution of two-mode continuous-variable entanglement in the presence of linear cross-talk and channel imperfections. We show how cross-talk degrades entanglement and leads to necessity of optimization of the initial entangled resource. We suggest a method for compensating the cross-talk by a phase-flipping beamsplitter, which can optimally remove the negative effect of cross-talk once the modes undergo almost the same channel attenuation.