We present a scheme for direct and confidential communication between Alice and Bob, where there is no need for establishing a shared secret key first, and where the key used by Alice even will… Expand

An alternative quantum key distribution protocol, where Alice and Bob use two mutually unbiased bases with one of them encoding a ‘0’ and the other one encoding a‘1’, which allows for more noise in the transmission line, thereby increasing the possible distance between Alice andBob without the need for intermediate nodes.Expand

Stochastic finite-state generators are compressed descriptions of infinite time series. Alternatively, compressed descriptions are given by quantum finite- state generators [K. Wiesner and J. P.… Expand

A ball type valve for high pressure lines is designed so that the spherical valve member is offset from the centerline of the valve stem in such a manner that the cylindrical flow passage is perpendicular to the flow axis of the inlet and outlet passages.Expand

A new approach to the implementation of quantum gates is proposed in which decoherence during the gate operations is strongly reduced by making use of an environment induced quantum Zeno effect that confines the dynamics effectively to a decoherent-free subspace.Expand

It is shown that a system of two atoms trapped inside an optical cavity can be designed such that a dark period prepares the atoms in a maximally entangled ground state.Expand

It is shown how the states of the subspace can be entangled with the help of weak laser pulses, using the high decay rate of the cavity field and strong coupling between the atoms and the resonator mode.Expand

Recently we predicted a random blinking, i.e., macroscopic quantum jumps, in the fluorescence of a laser-driven atom-cavity system [Metz et al., Phys. Rev. Lett. 97, 040503 (2006)]. Here we analyze… Expand

The possibility to perform distributed quantum computing using only single-photon sources (atom-cavity-like systems, linear optics, and photon detectors), which does not require explicit qubit-qubit interactions, a priori entangled ancillas, nor the feeding of photons into photon sources.Expand