Quantum Interference and Inelastic Scattering in a Model Which-Way Device

A which-way device is one which is designed to detect which of 2 paths is taken by a quantum particle, whether Schr\"odinger's cat is dead or alive. One possible such device is represented by an Aharonov-Bohm ring with a quantum dot on one branch. A charged cantilever or spring is brought close to the dot as a detector of the presence of an electron. The conventional view of such a device is that any change in the state of the cantilever implies a change in the electron state which will in turn destroy the interference effects. In this paper we show that it is in fact possible to change the state of the oscillator while preserving the quantum interference phenomenon.Comment: 5 pages, 7 figures, Localisation 2002 Toky

Finite Size Scaling Analysis of the Anderson Transition

This chapter describes the progress made during the past three decades in the finite size scaling analysis of the critical phenomena of the Anderson transition. The scaling theory of localisation and the Anderson model of localisation are briefly sketched. The finite size scaling method is described. Recent results for the critical exponents of the different symmetry classes are summarised. The importance of corrections to scaling are emphasised. A comparison with experiment is made, and a direction for future work is suggested.Comment: 12 pages, 1 figure. "Fifty Years of Anderson localization", edited by E. Abrahams (World Scientific, Singapore, 2010

Disorder and interactions in one-dimensional systems

Published versio

Diffraction and database analyses of photoactive biphenyl compounds and novel carbaborane structures

The research involved in this thesis is mainly concerned with crystallography and the analysis using crystallographic techniques and methods. The work in this thesis is centered mainly on two types of chemical compounds, photoactive compounds and carbaboranes. The first is the photoactive compounds of biphenyl, its derivatives and similar compounds; these compounds have been studied by diffraction and database analysis. The photochemistry and subsequent structural analysis of biphenyls has been studied in collaboration with Professor Peter Wan at the University of Victoria, Canada. In this study Professor Wan and his group conducted all synthesis and spectroscopic analysis, including the photochemical analysis. In a similar study although not with biphenyls, the a-azidocinnamates were investigated in collaboration with Professor Meth-Cohn of the University of Sunderland. Professor Meth-Cohn and his group conducted all synthesis and spectroscopic analysis. The biphenyl type compounds have also been studied using database analysis to examine the bond lengths, torsion angles, inter-/intra-molecular interactions and general packing conformations and interactions within these structures and this analysis was used to study several conformational anomalies that exist in biphenyl derivative compounds. The second chemical type is carbaboranes; these compounds have been examined in collaboration with Professor Wade's group at the University of Durham. The analysis of carbaboranes centers mainly on hydrogen bonding however also expands into several novel carbaborane structures. Professor Wade and his group carried out the synthesis and spectroscopic analysis

Quantum gears: a simple mechanical system in the quantum regime

Abstract. The quantum mechanics of a simple mechanical system is considered. A group of gears can serve as a model for several different systems such as an artifically constructed nanomechanical device or a group of ring molecules. It is shown that the classical motion of the gears in which the angular velocities are locked together does not correspond to

Plasmodium falciparum:Rosettes do not protect merozoites from invasion-inhibitory antibodies

Rosetting is a parasite adhesion phenotype associated with severe malaria in African children. Why parasites form rosettes is unknown, although enhanced invasion or immune evasion have been suggested as possible functions. Previous work showed that rosetting does not enhance parasite invasion under standard in vitro conditions. We hypothesised that rosetting might promote invasion in the presence of host invasion-inhibitory antibodies, by allowing merozoites direct entry into the erythrocytes in the rosette and so minimising exposure to plasma antibodies. We therefore investigated whether rosetting influences invasion in the presence of invasion-inhibitory antibodies to MSP-1. We found no difference in invasion rates between isogenic rosetting and non-rosetting lines from two parasite strains, R29 and TM284, in the presence of MSP-1 antibodies (P=0.62 and P=0.63, Student's t test, TM284 and R29, respectively). These results do not support the hypothesis that rosettes protect merozoites from inhibitory antibodies during invasion. The biological function of rosetting remains unknown