Witnessing quantum capacities of correlated channels
  We test a general method to detect lower bounds of the quantum channel capacity for two-qubit correlated channels. We consider in particular correlated dephasing, depolarising and amplitude damping channels. We show that the method is easily implementable, it does not require a priori knowledge about the channels, and it is very efficient, since it does not rely on full quantum process tomography. 
Chiara Macchiavello and Massimiliano F. Sacchi
quant-ph