Arbitrarily perfect quantum communication using unmodulated spin chains, a collaborative approach

Abstract

We shall consider a quantum communication channel constituted by two open spin chains with nearest neighbour interactions and fixed coupling strengths, connected to several users. Assuming that the users of this quantum data bus can apply simple gates on sites of the chain that they are connected to, we will see that it is possible to gain information on the position of the qubit during the transmission, and to use this information to accelerate the communication process. We will also see that performing frequent measurements on the system affects the dynamics of propagation of quantum information in an interesting way.