Geometric bonding effects in the X2A1, A2∑+u, and B2IIg states of Li2F

Published ab-initio and pseudopotential calculations for the dialkali halide systems suggest that the preferred co-linear geometry is for the metal to approach the metal end of the alkali halide. Here, ab-initio calculations on the Li2F system reveal that the well depth on the halide side in this radical is much deeper and is a local saddle-point associated with the ionic non-linear global minima. Although many features of the pseudopotential surfaces are confirmed, significant differences are apparent including the existence of a linear excited state instead of a triangular one, a considerably deeper global minimum some 50% lower in energy and a close approach between the X2A1 and the states, with the minimum 87 kJ mol-1 below the ground state asymptote. All the results can be rationalised as the avoided crossings between a long range, covalent potential dominant within the LiLiF geometry and an ionic state that forms the global minimum. Calculations on the 3rd 2A' potential indicate that even for Li + LiF collisions at ultracold temperatures the collision dynamics could involve as many as three electronic states.

Experimental Realization of Dicke States of up to Six Qubits for Multiparty Quantum Networking

We report the first experimental generation and characterization of a six-photon Dicke state. The produced state shows a fidelity of F=0.56 +/- 0.02 with respect to an ideal Dicke state and violates a witness detecting genuine six-qubit entanglement by 4 standard deviations. We confirm characteristic Dicke properties of our resource and demonstrate its versatility by projecting out four- and five-photon Dicke states, as well as four-photon Greenberger-Horne-Zeilinger and W states. We also show that Dicke states have interesting applications in multiparty quantum networking protocols such as open-destination teleportation, telecloning, and quantum secret sharing.

Leading integrated schools: a study of the multicultural perspectives of Northern Irish principals

This article is concerned with the sustained peace education initiative of integrated schooling and in particular with leadership responses to cultural diversity. Using a case study group of principals of integrated (mixed Catholic, Protestant and other) schools in Northern Ireland, the author explores how principals perceive and lead their visions of integrated education. A combined framework of multicultural and school leadership theory is employed to analyse the findings. The perceptions of the principals reported are consistent with liberal interpretations of multiculturalism, although there is also evidence of a more pluralist perspective. Core liberal values appear to be central to the leadership style of these principals, in line with values-led contingency models of leadership. The article suggests that a sole emphasis on common humanity is an inadequate approach to peace education. It tentatively suggests a relationship between leadership styles and approaches to multiculturalism, and argues that a synthesis of multicultural and leadership theory can usefully guide the development of peace education leadership.

Ethnic habitus and young children: a case study of Northern Ireland

This article presents the findings of an exploratory survey of the ethnic attitudes and identities of a random sample (n=352) of three–six-year-old children in Northern Ireland. The survey represents one of the first of its kind to explore how young children's awareness of ethnic differences develops in contexts where ethnicity is not marked by visible, physical differences. In drawing upon the notion of an ‘ethnic habitus’, the article shows how young children from the two majority ethno-religious groups in the region – Catholic and Protestants – are already acquiring the cultural dispositions and habits of their respective groups even though, at the earlier ages, they have little awareness or understanding of what these dispositions represent. The article shows that young children are capable of developing ethnic identities and prejudices in the absence of physical cues and discusses the implications of these findings for practice as well as for understanding the effects of racial and ethnic divisions on young children in other social contexts.