Suppression of superconductivity at nematic critical point in underdoped cuprates

A nematic quantum critical point is anticipated to exist in the superconducting dome of some high-temperature superconductors. The nematic order competes with the superconducting order and hence reduces the superconducting condensate at $T = 0$. Moreover, the critical fluctuations of nematic order can excite more nodal quasiparticles out of the condensate. We address these two effects within an effective field theory and show that superfluid density $\rho^s(T)$ and superconducting temperature $T_c$ are both suppressed strongly by the critical fluctuations. The strong suppression of superconductivity provides a possible way to determine the nematic quantum critical point.Comment: 6 pages, 4 figure

Time-dependent orientation coupling in equilibrium polymer melts

The motion in concentrated polymer systems is described by either the Rouse or the reptation model, which both assume that the relaxation of each polymer chain is independent of the surrounding chains. This, however, is in contradiction with several experiments. In this Letter, we propose a universal description of orientation coupling in polymer melts in terms of the time-dependent coupling parameter κ(t). We use molecular dynamics simulations to show that the coupling parameter increases with time, reaching about 50% at long times, independently of the chain length or blend composition. This leads to predictions of component dynamics in mixtures of different molecular weights from the knowledge of monodisperse dynamics for unentangled melts. Finally, we demonstrate that entanglements do not play a significant role in the observed coupling. © 2010 The American Physical Societ

A search engine for 3D models of museum artefacts

The National Museum of Ireland has about 5 million artifacts distributed across different physical locations. Essentially this means that only small fraction of these are accessible to the public at any time. Digital Libraries support the 3D browsing and retrieval of cultural museum artefacts and offer a potential solution to this problem. This paper describes a final year project where the objective was to build a search engine that: (1) could operate over a digital library storing digitized 3D model representations of objects, and (2) could be integrated with the existing DigiFact system architecture based in CDVP at DCU