Enhanced multipartite quantum correlations by non-Gaussian operations

We study how conditional photon operations can affect multipartite quantum correlations, specifically nonlocality and entanglement, of the continuous variable GHZ states. We find that the violation of the Mermin-Klyshko inequality revealing the multipartite nonlocality can be made stronger with photon subtraction applied on each mode of the original GHZ states, particularly in a weak squeezing regime. Photon addition applied on local modes also turns out to enhance the degree of multipartite nonlocality in a broad range of parameters. We further investigate the effects of the photon operations on the degree of multipartite entanglement by looking into the Gaussian tangle, the fidelity of teleportation network, and the quadrature correlations. We find that photon subtraction applied on two modes enhances those entanglement characteristics in a practical squeezing regime while there is no improvement made by photon addition.Comment: 11 pages, 10 figures, to appear in Phys. Rev.

Religious Service Attendance and Volunteering: A Growth Curve Analysis

Despite methodological advances in studying the relationship between religious attendance and volunteering, its dynamic nature still needs to be elucidated. We apply growth curve modeling to examine whether trajectories of religious attendance and volunteering are related to each other over a 15-year period in a nationally representative sample from the Americans’ Changing Lives data (1986-2002). Multivariate results showed that the rates of change in religious attendance and volunteering were positively related, and excluding religious volunteering did not alter the finding. It was also found that the initial level of religious attendance was positively associated with the rate of increase in volunteer hours over the period. Mediation analyses revealed that participation in voluntary associations explained the dynamic relationships between religious attendance and volunteering. These results provide evidence that involvement in organized religion and volunteering are dual activities that change together over the adult life course