Multi-parties Controlled Dense Coding via Maximal Slice States and the Physical Realization Using the Optical Elements

An efficient scheme for controlled dense coding is presented with the aid of the introduction of auxiliary particles, appropriate local unitary operations and measurement basis. In this proposal, the four-qubits maximal slice state, which belongs to partially entangled states, is used as quantum channel. The concrete implementation procedures for our scheme with one sender, one receiver and two controllers are given in detail, and the average transmitted classical information from the sender to the receiver is calculated. Additionally, the physical realization of this proposal is discussed based on the optical elements.