of this state for information quality. A protection that has been developed involves the use of continuous variable information (rather than a typical discrete variable) creating a superimposed coherent intermediate state. This involves making a phase shift in the received information and then adding a mixing step upon reception using a preferred state, which could be an odd or even coherent state, that will be "conditioned to the classical information of the sender" creating a two mode state that contains the originally sent information. There have also been developments with teleporting information between systems that already have quantum information in them. Experiments done by Feng, Xu, Zhou et al. have demonstrated that teleportation of a qubit to a photon that already has a qubit worth of information is possible due to using an optical qubit-ququart entangling gate. This quality can increase computation possibilities as calculations can be done based on previously stored information allowing for improvements on past calculations. See also Superdense coding Quantum complex network Quantum mechanics Introduction to quantum mechanics Quantum computer Quantum cryptography Quantum nonlocality Heisenberg uncertainty principle Wheeler–Feynman absorber theory References Specific General Review on theory and experiments: Theoretical proposal: This is the seminal paper that laid out the entanglement protocol. () Shi-Biao Zheng (2004) "Scheme for approximate conditional teleportation of an unknown atomic state without the Bell-state measurement", Phys. Rev. A 69, 064302 First experiments with photons: D. Bouwmeester, J.-W. Pan, K. Mattle, M. Eibl, H. Weinfurter, A. Zeilinger, Experimental Quantum Teleportation, Nature 390, 6660, 575–579 (1997). D. Boschi, S. Branca, F. De Martini, L. Hardy, & S. Popescu, Experimental Realization of Teleporting an Unknown Pure Quantum State via Dual classical and Einstein–Podolsky–Rosen channels, Phys. Rev. Lett. 80, 6, 1121–1125 (1998) First experiments with atoms: External links Loophole-free Bell test - Kavli Institute of Nanoscience "Spooky action and beyond" – Interview with Prof. Dr. Anton Zeilinger about quantum teleportation. Date: 2006-02-16 Quantum Teleportation at IBM Physicists Succeed In Transferring Information Between Matter And Light Quantum telecloning: Captain Kirk's clone and the eavesdropper Teleportation-based approaches to universal quantum computation Teleportation as a quantum computation Quantum teleportation with atoms: quantum process tomography Entangled State Teleportation Fidelity of quantum teleportation through noisy channels by TelePOVM— A generalized quantum teleportation scheme Entanglement Teleportation via Werner States Quantum Teleportation of a Polarization State The Time Travel Handbook: A Manual of Practical Teleportation & Time Travel letters to nature: Deterministic quantum