Multi-critical point in a diluted bilayer Heisenberg quantum antiferromagnet

The S=1/2 Heisenberg bilayer antiferromagnet with randomly removed inter-layer dimers is studied using quantum Monte Carlo simulations. A zero-temperature multi-critical point (p*,g*) at the classical percolation density p=p* and inter-layer coupling g* approximately 0.16 is demonstrated. The quantum critical exponents of the percolating cluster are determined using finite-size scaling. It is argued that the associated finite-temperature quantum critical regime extends to zero inter-layer coupling and could be relevant for antiferromagnetic cuprates doped with non-magnetic impurities.Comment: 4 pages, 6 figures. v2: only minor changes; accepted for publication in Phys. Rev. Let

The co-evolution of third stream activities in UK higher education

This paper explores the co-evolution of third stream activities in UK higher education from 1970 to 2008. Drawing on interviews and archival analysis it identifies four distinct periods through which third stream activities have co-evolved. The research suggests that the co-evolution of the third stream mission in universities is inextricably linked to the emerging requirement for universities to demonstrate they have a purpose in society. It concludes that the rise of third stream activities has presented both universities and government with a means of doing this

After renaissance: China's multilateral offensive in the developing world1

Why does a re-emerging China pursue institutional strategies to expand its multilateral ties all over the world? This study explains the genesis of China's new multilateral diplomacy toward Africa, Latin America, and the Middle East. The central argument of the study is that many strands of structural arguments drawn from realist, liberal, and constructivist insights cannot provide complete explanations about China's multilateral activism without recourse to cognitive feedback dynamics. China fed its regional experiences of multilateralism back into its global policy formation. This experiment-based approach has been a pervasive feature in Chinese multilateral diplomacy as well as Chinese domestic reforms during the post-Mao period. The cognitive feedback model developed in this study intends to complement the prominent structural explanations by identifying micro-level dynamics and seeks to contribute to today's debate over power transition and international order. © European Consortium for Political Research, SAGE Publications 2011.link_to_subscribed_fulltex