Entangled quantum states are an important component of quantum computing techniques such as quantum error-correction, dense coding and quantum teleportation. We describe how to generate fully entangled states in the Hilbert space C N ⊗ C N starting from a unitary matrix and show that they form an orthonormal basis in this space. Disentanglement is also discussed. Moreover we also calculate the Wigner function of fully entangled states.

Physica ScriptaJan 1, 20041 citation

arXiv:quant-ph/0003070 · Journal of Physics A Mathematical and General

All teleportation and dense coding schemes

R F Werner

Published Aug 24, 2001• 270 citations

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Abstract

DOI: 10.1088/0305-4470/34/35/332

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A set of protocols for teleportation and dense coding schemes based on a multiparticle quantum channel, represented by the

N

-particle entangled states of the GHZ class, is introduced. Using a found representation for the GHZ states, it was shown that for dense coding schemes enhancement of the classical capacity of the channel due from entanglement is

N/N-1

. Within the context of our schemes it becomes clear that there is no one-to one correspondence between teleportation and dense coding schemes in comparison when the EPR channel is exploited. A set of schemes, for which two additional operations as entanglement and disentanglement are permitted, is considered.