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Long distance communication using quantum systems has been an area of great interest. The use of quantum repeaters in quantum systems is essential for successful long distance communication. The use of quantum memories in quantum repeaters faces a problem of entanglement loss. The remedy for entanglement loss is the entanglement distillation. In this paper we have described a protocol for entanglement distillation. The pairs of W, Bell and GHZ type entangled states were used as channels and sited their probabilistic success in entanglement distillation of a two qubit non-maximally entangled unknown state. The results obtained from quantum distillation using different quantum channels are compared and the best protocol for quantum distillation can be used in quantum memories which are used in quantum repeaters for efficient long distance communication. [ABSTRACT FROM PUBLISHER]

We propose and demonstrate a local transformation of two EPR photon pairs to three-photon W state. The key issue of our scheme is that it requires only one polarization dependent beamsplitter to perform the necessary local operation. Using a quantum state tomography, the fidelity of the prepared three-photon state was estimated as 0.778±0.043. The expectation value of the witness operator of W3 was -0.111±0.043. [ABSTRACT FROM AUTHOR]