Multipartite maximally entangled states in symmetric scenarios

摘要

We consider the class of (N + 1)-partite states suitable for protocols where there is a powerful party, thenauthority, and the other N parties play the same role, namely, the state of their system lies in the symmetricnHilbert space.We show that, within this scenario, there is a “maximally entangled state” that can be transform byna local operations and classical communication protocol into any other state. In addition, we show how to use thenprotocol efficiently, including the construction of the state, and discuss security issues for possible applicationsnto cryptographic protocols. As an immediate consequence we recover a sequential protocol that implements then1-to-N symmetric cloning.