Three Miles Apart ... and Beyond: School Inequalities in Dublin 15

This ethnographic research, carried out in 2010-2011, looks at how two secondary schools deal with increasing numbers of international students. Both located in Dublin 15, the area with the highest percentage of migrants in Ireland, and located only three miles apart from each other, the two schools illustrate the heterogeneity of wealth distribution within the district: Oaktree College is located within a middle-class neighbourhood, and Newtown School located in a disadvantaged and much poorer neighbourhood

Observation of Free-Space Single-Atom Matterwave Interference

We observe matterwave interference of a single cesium atom in free fall. The interferometer is an absolute sensor of acceleration and we show that this technique is sensitive to forces at the level of $3.2\times10^{-27}$ N with a spatial resolution at the micron scale. We observe the build up of the interference pattern one atom at a time in an interferometer where the mean path separation extends far beyond the coherence length of the atom. Using the coherence length of the atom wavepacket as a metric, we directly probe the velocity distribution and measure the temperature of a single atom in free fall.Comment: 5 pages, 4 figure

Three Miles Apart ... and Beyond: School Inequalities in Dublin 15

This ethnographic research, carried out in 2010-2011, looks at how two secondary schools deal with increasing numbers of international students. Both located in Dublin 15, the area with the highest percentage of migrants in Ireland, and located only three miles apart from each other, the two schools illustrate the heterogeneity of wealth distribution within the district: Oaktree College is located within a middle-class neighbourhood, and Newtown School located in a disadvantaged and much poorer neighbourhood

Resolving the wave-vector in negative refractive media: The sign of Z\sqrt{Z}

We address the general issue of resolving the wave-vector in complex electromagnetic media including negative refractive media. This requires us to make a physical choice for the sign of a square-root imposed merely by conditions of causality. By considering the analytic behaviour of the wave-vector in the complex plane, it is shown that there are a total of eight physically distinct cases in the four quadrants of two Riemann sheets.Comment: 3 pages, 2 figures, RevTe

Anomalous wave propagation in quasiisotropic media

Based on boundary conditions and dispersion relations, the anomalous propagation of waves incident from regular isotropic media into quasiisotropic media is investigated. It is found that the anomalous negative refraction, anomalous total reflection and oblique total transmission can occur in the interface associated with quasiisotropic media. The Brewster angles of E- and H-polarized waves in quasiisotropic media are also discussed. It is shown that the propagation properties of waves in quasiisotropic media are significantly different from those in isotropic and anisotropic media.Comment: 15 pages, 4 figure

Electric-Field Affected Low-Energy Collisions between Co-Trapped Ammonia and Rubidium

This thesis describes the effect of an electric field on the interaction between rubidium and ammonia at 100 mK. The ability to study low energy interactions between molecules and atoms provides new tools to understand how the processes that govern these interactions work. For example, the use of external electric and magnetic fields provides tools to spatially orient molecules to show how this affects the dynamics of the interaction. The use of electric fields have been proposed to affect dipole-dipole interactions, however we have showed that the space-orienting effect of the field can have a significant effect even in the absence of dipole-dipole interaction. To measure this effect, we trap ammonia molecules in a single quantum state using an electrostatic trap. Rubidium atoms are trapped in a magnetic trap which is overlayed with the ammonia trap. The two samples then interact with minimal center of mass collision energy and we measure the elastic and inelastic cross sections by careful analysis of the ammonia trap-loss profile

Focusing and phase compensation of paraxial beams by a left-handed material slab

On the basis of angular spectrum representation, a formalism describing paraxial beams propagating through an isotropic left-handed material (LHM) slab is presented. The treatment allows us to introduce the ideas of beam focusing and phase compensation by LHM slab. Because of the negative refractive index of LHM slab, the inverse Gouy phase shift and the negative Rayleigh length of paraxial Gaussian beam are proposed. It is shown that the phase difference caused by the Gouy phase shift in right-handed material (RHM) can be compensated by that caused by the inverse Gouy phase shift in LHM. If certain matching conditions are satisfied, the intensity and phase distributions at object plane can be completely reconstructed at the image plane.Comment: 12 pages, 4 figure