A Possible Crypto-Superconducting Structure in a Superconducting Ferromagnet

We have measured the dc and ac electrical and magnetic properties in various magnetic fields of the recently reported superconducting ferromagnet RuSr2GdCu2O8. Our reversible magnetization measurements demonstrate the absence of a bulk Meissner state in the compound below the superconducting transition temperature. Several scenarios that might account for the absence of a bulk Meissner state, including the possible presence of a sponge-like non-uniform superconducting or a crypto-superconducting structure in the chemically uniform Ru-1212, have been proposed and discussed.Comment: 8 pages, 5 PNG figures, submitted to Proceedings of the 9th Japan-US Workshop on High-Tc Superconductors, Yamanashi, Japan, October 13-15, 1999; accepted for publication in Physica C (December 24, 1999

Developing Excellent Academic Leaders in Turbulent Times

The higher education sector needs good academic leaders. Unfortunately, the development and support of good leadership has been largely missing, despite its criticality in preparing institutions for these turbulent times. This commentary explores some of the challenges facing the sector with respect to academic leadership. It profiles some of the issues that are emerging with respect to building a robust sector, including addressing higher education's poor performance with respect to viable and well-considered strategy, academic management and the support of vulnerable academic members. It argues that these issues may stem from poor academic leadership and maps some of the reasons for this challenge. Suggestions as to how we might improve the higher education environment through enhanced valuing and support of good leadership are offered. 

Twisted Reality and the Second-Order Condition

An interesting feature of the finite-dimensional real spectral triple (A,H,D,J) of the Standard Model is that it satisfies a “second-order” condition: conjugation by J maps the Clifford algebra CℓD(A) into its commutant, which in fact is isomorphic to the Clifford algebra itself (H is a self-Morita equivalence CℓD(A) -bimodule). This resembles a property of the canonical spectral triple of a closed oriented Riemannian manifold: there is a dense subspace of H which is a self-Morita equivalence CℓD(A) -bimodule. In this paper we argue that on manifolds, in order for the self-Morita equivalence to be implemented by a reality operator J, one has to introduce a “twist” and weaken one of the axioms of real spectral triples. We then investigate how the above mentioned conditions behave under products of spectral triples