Quantum Dynamics Simulation with Classical Oscillators

In a previous paper [J.S.Briggs and A.Eisfeld, Phys.Rev.A 85, 052111] we showed that the time-development of the complex amplitudes of N coupled quantum states can be mapped by the time development of positions and velocities of N coupled classical oscillators. Here we examine to what extent this mapping can be realised to simulate the "quantum" properties of entanglement and qubit manipulation. By working through specific examples, e.g. of quantum gate operation, we seek to illuminate quantum/classical differences which hitherto have been treated more mathematically. In addition we show that important quantum coupled phenomena, such as the Landau-Zener transition and the occurrence of Fano resonances can be simulated by classical oscillators

On the Equivalence of Quantum and Classical Coherence in Electronic Energy Transfer

To investigate the effect of quantum coherence on electronic energy transfer, which is the subject of current interest in photosynthesis, we solve the problem of transport for the simplest model of an aggregate of monomers interacting through dipole-dipole forces using both quantum and classical dynamics. We conclude that for realistic coupling strengths quantum and classical coherent transport are identical. This is demonstrated by numerical calculations for a linear chain and for the photosynthetic Fenna-Matthews-Olson (FMO) comple

Doing gender and development: understanding empowerment and local gender relations

A major dilemma in Gender and Development (GAD) work is why it is that sometimes women may feel better off colluding with gendered structures that ensure their continued subordination rather than seeking approaches that will allow them to break free of this. Kandiyoti (1988 Gender and Society 2 274-90) has identified this apparent collusion as 'patriarchal bargains', which offer women greater advantages than they perceive can be achieved by challenging the prevailing order. Such women are therefore reluctant to engage in empowering activities that may challenge their gendered bargain. This paper explains this dilemma in the context of GAD work undertaken with Bedouin women in Southern Egypt

Building and assessing subject knowledge in mathematics for pre-service students

In planning and teaching curriculum courses for pre-service primary teachers, both within a one-year Post Graduate Certificate of Education (PGCE) programme, and in a four-year undergraduate degree leading to Qualified Teacher Status (QTS), we have always been aware that mathematics presents particular problems because of the experiences and attitudes students bring to the subject. We have always tried to balance students’ learning about how children learn mathematics in school, with reflection on their own experiences as learners, and with understanding of the mathematical content of the curriculum. In the past, mathematical content has generally been approached indirectly through discussion of activities and materials appropriate for the primary classroom. However the recent introduction in the U.K. of a National Curriculum for Primary Mathematics in Initial Teacher Training (ITT) which places considerable emphasis on students’ subject knowledge, has meant that we have had to rethink the balance within courses, and to place much more overt emphasis on developing students’ mathematical knowledge. In this paper we describe the way in which we have approached building and assessing mathematical knowledge during the pilot phase of the ITT National Curriculum, examine some of the students’ responses to our approach, and discuss the issues this has raised

Able and gifted: judging by appearances?

In this article I reflect upon an aspect of my research involving Year 6 pupils identified by their teachers as ‘able’ or ‘gifted’ in mathematics, using ‘able’ to refer to high achievers and ‘gifted’ to exceptionally high achievers. I discuss the differences I observed between the able and gifted when solving mathematical tasks, and consider what these differences may mean for professionals involved in identifying gifted pupils. I speculate that teachers’ judgements are highly influenced by those aspects of achievement that are readily visible, such as answering questions quickly, and discuss the potential problems associated with judging by appearances

XMM-Newton First Observation in the Pleiades

We present the first results from a 40 ks Guaranteed Time XMM-Newton pointing in the Pleiades. We detect almost all early-mid dM members in the field and several very low mass (VLM) stars - including the brown dwarf (BD) candidate Roque 9 - and investigate the variation of X-ray activity levels, hardness ratios and flare frequency with spectral type down to the BD regime.Comment: 5 pages, 6 figures, to be published in proceedings of `Stellar Coronae in the Chandra and XMM-Newton Era

Theoretical Determination of the Boundary of the Geomagnetic Field in a Steady Solar Wind

Theoretical determination of the boundary of the geomagnetic field in a steady solar win

The nodal structure of doubly-excited resonant states of helium

The authors examine the nodal structure of accurate helium wavefunctions calculated by direct diagonalization of the full six-dimensional problem. It is shown that for fixed interelectronic distance R (or hyperspherical radius R) the symmetric doubly-excited resonant states have well defined lambda , mu nodal structure indicating a near separability in prolate spheroidal coordinates. For fixed lambda , however, a clear mixing of R, mu nodes is demonstrated. This corresponds to a breakdown of the adiabatic approximation and can be understood in terms of the classical two-electron motion