Generalized W-states and Quantum Communication Protocols

TL;DR

This paper explores the use of generalized W-states in multi-qubit quantum teleportation and superdense coding, identifying their limitations and specific conditions for effective quantum communication.

Contribution

It introduces conditions for using generalized W-states as resources in teleportation and superdense coding, highlighting their limitations for maximal protocols.

Findings

Limited class of multi-qubit states can be teleported

At most n+1 classical bits transmitted with n qubits

States unsuitable for maximal teleportation when n > 3

Abstract

We consider W-states and generalized W-states for $n$-qubit systems. We obtain conditions to use these states as quantum resources to teleport unknown states. Only a limited class of multi-qubit states can be teleported. For $one$-qubit states, we use protocols which are simple extensions of the conventional teleportation protocol. We also show that these resource states can be used to transmit {\em at most} $n + 1$ classical bits by sending $n$ qubits if the appropriate conditions are met. Therefore these states are not suitable for maximal teleportation or superdense coding when $ n > 3$.