Quantum information is a rapidly advancing area of interdisciplinary research. It may lead to real-world applications for communication and computation unavailable without the exploitation of quantum… (More)

S. L. Braunstein,1 C. M. Caves,2 R. Jozsa,3 N. Linden,4 S. Popescu,4,5 and R. Schack2,6 1SEECS, University of Wales, Bangor LL57 1UT, United Kingdom 2Center for Advanced Studies, Department of… (More)

Quantum teleportation is analyzed for states of dynamical variables with continuous spectra, i contrast to previous work with discrete (spin) variables. The entanglement fidelity of the schem is… (More)

We study entanglement properties of mixed density matrices obtained from combinatorial Laplacians. This is done by introducing the notion of the density matrix of a graph. We characterize the graphs… (More)

A photon in an arbitrary polarization state cannot be cloned perfectly. But suppose that at our disposal we have several copies of a photon in an unknown state. Is it possible to delete the… (More)

Quantum key distribution (QKD) offers the promise of absolutely secure communications. However, proofs of absolute security often assume perfect implementation from theory to experiment. Thus,… (More)

STEFANO PIRANDOLA1*, STEFANO MANCINI2, SETH LLOYD1,3 AND SAMUEL L. BRAUNSTEIN4 Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA… (More)

We employ a basic formalism from convex analysis to show a simple relation between the entanglement of formation EF and the conjugate function E∗ of the entanglement function E(ρ) = S(TrAρ). We then… (More)

641 It has been over two decades since the discovery of quantum tele portation, in what is arguably one of the most interesting and exciting implications of the ‘weirdness’ of quantum mechanics.… (More)