U(2) gates are derived, which derive upper and lower bounds on the exact number of elementary gates required to build up a variety of two- and three-bit quantum gates, the asymptotic number required for n-bit Deutsch-Toffoli gates, and make some observations about the number of unitary operations on arbitrarily many bits.Expand

An unknown quantum state \ensuremath{\Vert}\ensuremath{\varphi}〉 can be disassembled into, then later reconstructed from, purely classical information and purely nonclassical Einstein-Podolsky-Rosen… Expand

It is proved that an EPP involving one-way classical communication and acting on mixed state M (obtained by sharing halves of Einstein-Podolsky-Rosen pairs through a channel) yields a QECC on \ensuremath{\chi} with rate Q=D, and vice versa, and it is proved Q is not increased by adding one- way classical communication.Expand

It is shown that in principle any two nonorthogonal quantum states suffice, and a practical interferometric realization using low-intensity coherent light pulses is described.Expand

The set of states accessible from an initial EPR state by one-particle operations are characterized and it is shown that in a sense they allow two bits to be encoded reliably in one spin-1/2 particle.Expand

A related but simpler EPR scheme is described and it is proved it secure against more general attacks, including substitution of a fake EPR source and the original 1984 key distribution scheme of Bennett and Brassard, which uses single particles instead of EPR pairs.Expand

Upper and lower bounds on the yield of pure singlets ($\ket{\Psi^-}$) distillable from mixed states $M$ are given, showing $D(M)>0$ if $\bra{Psi-}M\ket-}>\half$.Expand

Any pure or mixed entangled state of two systems can be produced by two classically communicating separated observers, drawing on a supply of singlets as their sole source of entanglement.Expand

This paper finds the measurement which provides the optimal mutual information about the parity bit and calculates that information, and proves that this information decreases exponentially with the length of the string in the case where the single bit states are almost fully overlapping.Expand

Tverberg, H., On a coin tossing problem by G. Bennett, Discrete Mathematics 115 (1993) 293-294. For a certain class of games, Bennett proved that player B never has a smaller chance of winning than… Expand