Characterization and quantification of symmetric Gaussian state entanglement through a local classicality criterion

A necessary and sufficient condition for characterization and quantification of entanglement of any bipartite Gaussian state belonging to a special symmetry class is given in terms of classicality measures of one-party states. For Gaussian states whose local covariance matrices have equal determinants it is shown that separability of a two-party state and classicality of one party state are completely equivalent to each other under a nonlocal operation, allowing entanglement features to be understood in terms of any available classicality measure.Comment: 5 pages, 1 figure. Replaced with final published versio

On the P-representable subset of all bipartite Gaussian separable states

P-representability is a necessary and sufficient condition for separability of bipartite Gaussian states only for the special subset of states whose covariance matrix are $Sp(2,R)\otimes Sp(2,R)$ locally invariant. Although this special class of states can be reached by a convenient $Sp(2,R)\otimes Sp(2,R)$ transformation over an arbitrary covariance matrix, it represents a loss of generality, avoiding inference of many general aspects of separability of bipartite Gaussian states.Comment: Final version with new results added. Slightly more detailed than the accepted manuscript (to appear in Phys. Rev. A

Selective PARP-1 Targeting for Designing Chemo/Radio Sensitizing Agents

Poly(ADP-ribose) polymerase-1 (PARP-1) is a central signaling enzyme in a cell nucleus. PARP-1 is a target for the development of radio and chemo sensitizing agents in cancer treatment as well as providing protection from stroke. An SH3 domain and an SH3 ligand domain have now been discovered on the PARP-1 protein. These domains are involved in PARP-1 activation. This discovery makes possible the use of bioinformatics tools for the design of new drugs and strategies for drug target selection, specifically targeting the PARP-1 enzyme

Nonzero Classical Discord

Quantum discord is the quantitative difference between two alternative expressions for bipartite mutual information, given respectively in terms of two distinct definitions for the conditional entropy. By constructing a stochastic model of shared states, classical discord can be similarly defined, quantifying the presence of some stochasticity in the measurement process. Therefore, discord can generally be understood as a quantification of the system's state disturbance due to local measurements, be it quantum or classical. We establish an operational meaning of classical discord in the context of state merging with noisy measurement and thereby show the quantum-classical separation in terms of a negative conditional entropy.Comment: Replaced by the published versio