Electrical conductivity and thermal behavior of solid electrolytes based on alkali carbonates and sulfates

Both thermal stability and electrical conductivity of alkali ion conducting Na2CO3 and Na2SO4, were improved by adding alkaline earth carbonates and sulfates, respectively, as well as insulating materials like ¿-Al2O3. The admixing of divalent compounds causes two effects. First a more or less extended solution can exist depending on the radius of the alkaline earth ion and is accompanied by an increase in electrical conductivity. Secondly, a phase mixture with an excess of dopant was observed that shows an enhancement in conductivity and mechanical stability. This phenomenon known as composite effect was observed in the following systems: Na2CO3-BaCO3, Na2CO3-SrCO3, Na2SO4-BaSO4, Na2SO4-¿-Al2O3

Generation of field mediated three qubit entangled state shared by Alice and Bob

A scheme to generate shared tripartite entangled states, with two-trapped atoms in a cavity held by Alice (qubits A1 and A2) entangled to a single trapped atom in a remote lab owned by Bob (B), is proposed. The entanglement is generated through interaction of trapped atoms with two mode squeezed light shared by the two cavities. The proposed scheme is an extension of the proposal of ref. [W. Son, M. S. Kim, J. Lee, and D. Ahn, J. Mod. Opt. 49, 1739 (2002)], where the possibility of entangling two remote qubits using a bipartite continuous variable state was examined. While the global negativity detects the free entanglement of the three atom mixed state, the bound entanglement is detected by the negativity calculated from pure state decomposition of the state operator. The partial negativities calculated by selective partial transposition of the three atom mixed state detect the pairwise entanglement of qubit pairs A1B, A2B, and A1A2. The entanglement of three atoms is found to be W-like, no GHZ like quantum correlations being generated.Comment: 14 pages, 06 figures, section IV revised, Other minor changes to improve readabilit

Quantum random walk of two photons in separable and entangled state

We discuss quantum random walk of two photons using linear optical elements. We analyze the quantum random walk using photons in a variety of quantum states including entangled states. We find that for photons initially in separable Fock states, the final state is entangled. For polarization entangled photons produced by type II downconverter, we calculate the joint probability of detecting two photons at a given site. We show the remarkable dependence of the two photon detection probability on the quantum nature of the state. In order to understand the quantum random walk, we present exact analytical results for small number of steps like five. We present in details numerical results for a number of cases and supplement the numerical results with asymptotic analytical results

Multiphoton path entanglement by non-local bunching

Multiphoton path entanglement is created without applying post-selection, by manipulating the state of stimulated parametric down-conversion. A specific measurement on one of the two output spatial modes leads to the non-local bunching of the photons of the other mode, forming the desired multiphoton path entangled state. We present experimental results for the case of a heralded two-photon path entangled state and show how to extend this scheme to higher photon numbers.Comment: 4 pages, 5 figures, published versio

Role of Strigolactones in the Host Specificity of Broomrapes and Witchweeds

Root parasitic plants of the Orobanchaceae, broomrapes and witchweeds, pose a severe problem to agriculture in Europe, Asia and especially Africa. These parasites are totally dependent on their host for survival, and therefore, their germination is tightly regulated by host presence. Indeed, their seeds remain dormant in the soil until a host root is detected through compounds called germination stimulants. Strigolactones (SLs) are the most important class of germination stimulants. They play an important role in planta as a phytohormone and, upon exudation from the root, function in the recruitment of symbiotic arbuscular mycorrhizal fungi. Plants exude mixtures of various different SLs, possibly to evade detection by these parasites and still recruit symbionts. Vice versa, parasitic plants must only respond to the SL composition that is exuded by their host, or else risk germination in the presence of non-hosts. Therefore, parasitic plants have evolved an entire clade of SL receptors, called HTL/KAI2s, to perceive the SL cues. It has been demonstrated that these receptors each have a distinct sensitivity and specificity to the different known SLs, which possibly allows them to recognize the SL-blend characteristic of their host. In this review, we will discuss the molecular basis of SL sensitivity and specificity in these parasitic plants through HTL/KAI2s and review the evidence that these receptors contribute to host specificity of parasitic plants

Experimental violation of a spin-1 Bell inequality using maximally-entangled four-photon states

We demonstrate the first experimental violation of a spin-1 Bell inequality. The spin-1 inequality is a calculation based on the Clauser, Horne, Shimony and Holt formalism. For entangled spin-1 particles the maximum quantum mechanical prediction is 2.552 as opposed to a maximum of 2, predicted using local hidden variables. We obtained an experimental value of 2.27 $\pm 0.02$ using the four-photon state generated by pulsed, type-II, stimulated parametric down-conversion. This is a violation of the spin-1 Bell inequality by more than 13 standard deviations.Comment: 5 pages, 3 figures, Revtex4. Problem with figures resolve

Quantum filter for non-local polarization properties of photonic qubits

We present an optical filter that transmits photon pairs only if they share the same horizontal or vertical polarization, without decreasing the quantum coherence between these two possibilities. Various applications for entanglement manipulations and multi-photon qubits are discussed.Comment: 7 pages, including one figure, short discussion of error sources adde