In this paper, two general quantum teleportation schemes via two different non-maximally entangled states are proposed, and including a supercoding scheme is also investigated using a partial symmetric quantum channel.

A dense coding scheme which employs non-symmetric two-particle entangled state as quantum channel is advanced.

Drawing idea from the quantum secure direct communication(QSDC) and the dense coding,we propose a novel quantum secret sharing(QSS) scheme with high efficiency based on the GHZ states.

According to the theory that quantum entanglement can be used in quantum dense coding and increase the classical information capacity of a quantum channel, we discuss and compare the upper bound of capacity for dense coding in two case of using entangled input states and using product input states though a noiseless channel, when using a pure entanglement resource and get the result,i.

Controlled quantum dense coding via a non-maximal entangled state;

In Chapter 4, We discuss the schemes of probabilistically controlled dense coding utilizing GHZ-class state and cluster state as quantum channel,and discuss and analyze the average amount of the sent information.