Dark periods and revivals of entanglement in a two-qubit system

In a recent paper Yu and Eberly [Phys. Rev. Lett. 93, 140404 (2004)] have shown that two initially entangled and afterward not interacting qubits can become completely disentangled in a finite time. We study transient entanglement between two qubits coupled collectively to a multimode vacuum field, assuming that the two-qubit system is initially prepared in an entangled state produced by the two-photon coherences, and find the unusual feature that the irreversible spontaneous decay can lead to a revival of the entanglement that has already been destroyed. The results show that this feature is independent of the coherent dipole-dipole interaction between the atoms but it depends critically on whether or not collective damping is present.

The dark side of romantic relationships: The role of person and situational variable in the experience and expression of jealousy

The aim of this study was to further our understanding of the factors that influence the experience of jealousy in romantic relationships. More specifically, the person variables of neuroticism, gender, and attachment style were examined, together with situational determinants such as past infidelity. The research also assessed the interaction between person and situadonal determinants of jealousy, and the relative importance of the various predictors. Questionnaires were completed by 102 undergraduate psychology students and an addidonal five participants from the researcher's social network. Consistent with past research, there was a positive association between neurodcism and chronic, emodonal, and behavioural jealousy. Furthermore, there was a posidve associadon between anxious attachment and jealousy, even when neurodcism was controlled. Past experience of infidelity and attachment dimensions had interacdve effects on jealousy. Interesdngly, the reladve importance of the predictors varied across the dimensions of jealousy. The results extend research in the area of person and situadonal determinants of jealousy, and are discussed in terms of attachment theory.