Fidelity improvement in remote preparation of 3-qubit non-maximally entangled states through noisy environment

In this paper, a controlled remote state preparation protocol for a 3-qubit non-maximally entangled state is discussed. The state belongs to a class of states which includes W-state in particular. The information of the state is available with Alice who intends to create the same at the site of a distant party Bob. There is a controller Candy of the protocol. The state is not possessed physically by any of the above-mentioned three parties involved in the protocol. The controller has two roles to play, one is to create a six-qubit entangled state and distribute the relevant qubits to other parties by which he creates an entangled quantum channel between the three parties. The controller also acts toward the end of the protocol by signaling the final action. The effect of noise has been considered through Kraus operators. It is shown through illustration that the fidelity of the process decreases with an increase in noise parameter. Further, by applications of weak and reversal measurements, it is observed that the effect of noise can be minimized. The case of W-state is specially treated. We use the IBMQ platform for verification of the circuit for the creation of entangled resource used in the protocol.