Quantum entanglement and classical communication through a depolarizing channel
Dagmar Bruß, Lara Faoro, Chiara Macchiavello, G. Massimo Palma · Journal of Modern Optics · 2000
We analyse the role of entanglement for transmission of classical information through a memoryless depolarizing channel. Using the isotropic character of this channel we prove analytically that the mutual information cannot be increased by encoding classical bits into entangled states of two qubits.