Communications in Physics 28
, 1-19 (2018)
COPING WITH NOISE IN JOINT REMOTE PREPARATION OF A GENERAL TWO-QUBIT STATE BY USING NONMAXIMALLY ENTANGLED QUANTUM CHANNEL
LE THANH DAT, NGUYEN VAN HOP AND NGUYEN BA AN
Noise is unavoidable in practice and its presence makes quantum protocols imperfect.
In this paper we consider a way to cope with typical types of noise in joint remote preparation
of an arbitrary 2-qubit state. The idea is to use nonmaximally (instead of maximally) entangled
states as the initial quantum channel. Because noise changes the initial quantum channel we can
beforehand tailor it to be nonmaximally entangled by introducing free parameters which, depending
on given types of noise, can be controlled so that due to the affect of noise the initial quantum
channel becomes closest to the maximally entangled one, thus optimizing the performance of the
joint remote state preparation protocol. The dependence of the optimal averaged fidelities on the
strength of various types of noise is represented by phase diagrams that clearly separate the quantum
domain from the classical one.