Proof-of-principle demonstration of measurement-device-independent   quantum key distribution using polarization qubits
  We perform a proof-of-principle demonstration of the measurement-device-independent quantum key distribution (MDI-QKD) protocol using weak coherent states and polarization-encoded qubits over two optical fiber links of 8.5 km each. Each link was independently stabilized against polarization drifts using a full-polarization control system employing two wavelength-multiplexed control channels. A linear-optics-based polarization Bell-state analyzer was built into the intermediate station, Charlie, which is connected to both Alice and Bob via the optical fiber links. Using decoy-states, a lower bound for the secret-key generation rate of 1.04x10^-6 bits/pulse is computed. 
T. Ferreira da Silva, D. Vitoreti, G. B. Xavier, G. C. do Amaral, G.   P. Tempor\~ao, and J. P. von der Weid
quant-ph