Generation and Applications of n-Qubit Hyperentangled Photon States

In recent years, a number of theoretical and experimentE demonstrations regarding the use of photonic entangle( states based on many qubits, spanning a large siz( Hilbert space has been provided. The entanglement of tw, particles in more than one degree of freedom, namel" hyperentanglement, is a useful technique which allows t( take full advantage of the possibilities offered by quar turn mechanics. Compared to multiphoton entangled states hyperentangled states offer important advantages as fa as purity and generation/detection rate are concerned. Th present work is intended to survey the most relevant exam ples of hyperentangled multiqubit photon states aimed at th verification of fundamental tests of quantum mechanics an the realization of important quantum information protocols.