Exact synthesis of multiqubit Clifford+T circuits

We prove that a unitary matrix has an exact representation over the Clifford+T gate set with local ancillas if and only if its entries are in the ring Z[1/sqrt(2),i]. Moreover, we show that one ancilla always suffices. These facts were conjectured by Kliuchnikov, Maslov, and Mosca. We obtain an algorithm for synthesizing a exact Clifford+T circuit from any such n-qubit operator. We also characterize the Clifford+T operators that can be represented without ancillas.Comment: 7 page

European governments and African demands for reparations

Reparations for colonial atrocities in Africa are now, for perhaps the first time, a serious topic of discussion in European politics. The claims of the Mau-Mau veterans from Kenya, and the descendants of the victims of the Herero Genocide in Namibia (1904-1907), make headline news[1]. Drawing on considerable legal and historical expertise, the cases represent a new professionalisation and seriousness of the campaign for African reparations. Gone is the inflated rhetoric of the 2001 Durban World Conference against Racism, Racial Discrimination, Xenophobia and Related Intolerance, which allowed European states to dismiss the issue as a means for some states to boost their diminishing international legitimacy. In the Mau-Mau case, indeed, the British government was recently forced, effectively, to declare itself guilty, but not liable, for its repression of the uprising. In other words, it, like its German counterpart, is concerned about opening the infamous ‘Pandora’ Box’, and creating a legal precedent which would precipitate an avalanche of claims from every corner of its former colonial world

‘The Sacred Spark of Wonder’: Local Museums, Australian Curriculum History, and Pre-Service Primary Teacher Education: A Tasmanian Case Study

This article explores the intersections between museum learning – in a distinctive Tasmanian setting, the possibilities of a new national History curriculum, and the evolving views and professional practices of pre-service primary teachers at one Australian university. Following a brief overview of the framework for local and Australian history that is embedded in the ACH, the relevant literature around museum education, and the specific museum context, the article draws upon a survey of second year pre-service primary teachers’ views towards history, museums, and a pedagogical planning task and analyses features of students’ work. It concludes with some wider reflections on the value of teacher education engaging in community partnerships with cultural institutions such as museums

The liberal middle classes and politics in three provincial towns : Newcastle, Bristol and York - c.1812-1841.

SIGLEAvailable from British Library Document Supply Centre- DSC:D97963 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Citizenship into practice in England: the continuing professional development challenge

This paper surveys the strategies adopted in England to support the development of teachers’ subject knowledge and confidence in relation to teaching Citizenship, which was introduced as a new statutory subject in the National Curriculum in 2002. It reviews examples of good practice and explores how a continuing professional development (CPD) strategy developed at several levels to support teachers and curriculum managers. It outlines the challenges and obstacles in relation to implementing effective Citizenship education in schools. It also underlines the fundamental importance of Citizenship education if young people are to understand and engage with contemporary events in the early Twenty First Century

Adsorption of organic molecules at the TiO2(110) surface: the effect of van der Waals interactions

Understanding the interaction of organic molecules with TiO2 surfaces is important for a wide range of technological applications. While density functional theory (DFT) calculations can provide valuable insight about these interactions, traditional DFT approaches with local exchange-correlation functionals suffer from a poor description of non-bonding van der Waals (vdW) interactions. We examine here the contribution of vdW forces to the interaction of small organic molecules (methane, methanol, formic acid and glycine) with the TiO2 (110) surface, based on DFT calculations with the optB88-vdW functional. The adsorption geometries and energies at different configurations were also obtained in the standard generalized gradient approximation (GGA-PBE) for comparison. We find that the optB88-vdW consistently gives shorter surface adsorbate-to-surface distances and slightly stronger interactions than PBE for the weak (physisorbed) modes of adsorption. In the case of strongly adsorbed (chemisorbed) molecules both functionals give similar results for the adsorption geometries, and also similar values of the relative energies between different chemisorption modes for each molecule. In particular both functionals predict that dissociative adsorption is more favourable than molecular adsorption for methanol, formic acid and glycine, in general agreement with experiment. The dissociation energies obtained from both functionals are also very similar, indicating that vdW interactions do not affect the thermodynamics of surface deprotonation. However, the optB88-vdW always predicts stronger adsorption than PBE. The comparison of the methanol adsorption energies with values obtained from a Redhead analysis of temperature programmed desorption data suggests that optB88-vdW significantly overestimates the adsorption strength, although we warn about the uncertainties involved in such comparisons.Comment: 32 pages, 8 figures; accepted in Surface Scienc

Does haste make waste? The human factors of overtaking land design

The aim of this research was to improve overtaking safety and efficiency through improvements in road signage, markings, geometry and speed control associated with the placement and layout of passing lanes. The approach of the research was to explore the effects of several types of overtaking lane treatments in the safety and controlled environment of a state-of-the-art driving simulator. It was found that under the most benign conditions there were no differential effects of the three treatments. With poorer visibility or more taxing road geometry, the drivers relied more heavily on the road markings and signage and the effects of the treatments become more pronounced. The sensitivity to the more "challenging" situations was borne out by the greater speed differential between merge area sections at these sites