  Quantum communication is a secure way to transfer quantum information and to
communicate with legitimate parties over distant places in a network. Although
communication over a long distance has already been attained, technical problem
arises due to unavoidable loss of information through the transmission channel.
Quantum repeaters can extend the distance scale using entanglement swapping and
purification scheme. Here we demonstrate the working of a quantum repeater by
the above two processes. We use IBM's real quantum processor `ibmqx4' to create
two pair of entangled qubits and design an equivalent quantum circuit which
consequently swaps the entanglement between the two pairs. We then develop a
novel purification protocol which enhances the degree of entanglement in a
noisy channel that includes combined errors of bit-flip, phase-flip and
phase-change error. We perform quantum state tomography to verify the
entanglement swapping between the two pairs of qubits and working of the
purification protocol.
