Study of controlled dense coding with some discrete tripartite and   quadripartite states
  The paper presents the detailed study of controlled dense coding scheme for different types of $3$ and $4-$ particle states. It consists of GHZ state, GHZ type states, Maximal Slice state, Four particle GHZ state and W class of states. It is shown that GHZ-type states can be used for controlled dense coding in a probabilistic sense. We have shown relations among parameter of GHZ type state, concurrence of the shared bipartite state by two parties with respect to GHZ type and Charlie's measurement angle $\theta$. We have seen that tripartite W state and quadripartite W state cannot be used in controlled dense coding whereas $\vert W_{n}\rangle_{ABC}$ states can be used probabilistically. Finally, we have investigated controlled dense coding scheme for tripartite qutrit states. 
Sovik Roy and Biplab Ghosh
quant-ph