Electronic reconstruction in correlated electron heterostructures

Electronic phase behavior in correlated-electron systems is a fundamental problem of condensed matter physics. We argue here that the change in the phase behavior near the surface and interface, i.e., {\em electronic reconstruction}, is the fundamental issue of the correlated-electron surface or interface science. Beyond its importance to basic science, understanding of this behavior is crucial for potential devices exploiting the novel properties of the correlated systems. % We present a general overview of the field, and then illustrate the general concepts by theoretical studies of the model heterostructures comprised of a Mott-insulator and a band-insulator, which show that spin (and orbital) orderings in thin heterostructures are generically different from the bulk and that the interface region, about three-unit-cell wide, is always metallic, demonstrating that {\em electronic reconstruction} generally occurs. % Predictions for photoemission experiments are made to show how the electronic properties change as a function of position, and the magnetic phase diagram is determined as a function of temperature, number of layers, and interaction strength. Future directions for research are also discussed.Comment: Proceedings of SPIE conference on Strongly Correlated Electron Materials: Physics and Nanoengineering, San Diego, CA, 31 July - 4 August, 200

Electronic Resources and Heterodox Economists

The idea of measuring scientific relevance by counting citations is gaining ever-growing consensus among economists, and thanks to the electronic bibliographic resources now available the procedure has become relatively simple and fast. However, when it comes to putting the idea into practice many challenging problems emerge. This paper uses five of the principal bibliographic electronic resources (EconLit, JSTOR, Web of Science, Scopus and Google Scholar) to test the practical applicability of this method for measuring relevance to the particular case of heterodox economics.heterodox economists; EconLit; JSTOR; Web of Science; Scopus; Google Scholar

Electronic publishing: technical constraints with policy consequences

This paper reviews the impact of two convergent trends in publication; the growth of 'electronic dissemination' through bodies such as Social Science Electronic Publishing, and the increasing electronic presence of normal journals. It assesses the prospects and difficulties surrounding emergent projects of fully-electronic refereed publications such as the new journal of the Society for Non-Linear Economic Dynamics. It discusses a project, current at the time, to convert the annual proceedings of a regular economics conference into a refereed electronic publication, and review the issues governing choice of medium, editorial standards and procedures, citation, authentication and copyright. This project subsequently matured into the refereed online journal Critique of Political Economy (COPE) [www.copejournal.org]COPE; TSSI; Electronic Publishing

Efficient approach for simulating distorted materials

The operation principles of nanoscale devices are based upon both electronic and mechanical properties of materials. Because these properties can be coupled, they need to be investigated simultaneously. At this moment, however, the electronic structure calculations with custom-made long-range mechanical distortions are impossible, or expensive at best. Here we present a unified formalism to solve exactly the electronic structures of nanomaterials with versatile distortions. We illustrate the formalism by investigating twisted armchair graphene nanoribbons with the least possible number of atoms. Apart from enabling versatile material distortions, the formalism is capable of reducing computational costs orders of magnitude in various areas of science and engineering.Comment: 4 pages, 2 figures, 2 table

Interplay between proton ordering and ferroelectric polarization in H-bonded KDP-type crystals

The origin of ferroelectricity in KH_2PO_4 (KDP) is studied by first-principles electronic structure calculations. In the low-temperature phase, the collective off-center ordering of the protons is accompanied by an electronic charge delocalization from the "near" and localization at the "far" oxygen within the O-H...O bonds. Electrostatic forces, then, push the K+ ions towards off-center positions, and induce a macroscopic polarization. The analysis of the correlation between different geometrical and electronic quantities, in connection with experimental data, supports the idea that the role of tunnelling in isotopic effects is irrelevant. Instead, geometrical quantum effects appear to play a central role.Comment: 8 pages, 2 postscript figures, submitted to the X Conference on Computational Materials Science, Villasimius, Sardinia (Italy), 200

Scanning Tunneling Microscopy and Spectroscopy of Graphene on Insulating Substrates

Graphene is a truly two-dimensional material with exceptional electronic, mechanical, and optical properties. As such, it consists of surface only and can be probed by the well developed surface-science techniques as, e.g., scanning tunneling microscopy. This method bridges the gap between the surface science community and the electronic device community and might lead to novel combined approaches. Here, I review some of the scanning tunneling microscopy (STM) and spectroscopy (STS) experiments on monolayer graphene samples. I will concentrate on graphene samples deposited on insulating substrates, since these are related to graphene device concepts. In particular, I will discuss the morphology of graphene on SiO$_2$ and other emerging substrates, some nanomechanical manipulation experiments using STM, and spectroscopic results. The latter can map the disorder potentials as well as the interaction of the electrons with the disorder which is most pronounced in the quantum Hall regime.Comment: Review, 12 page

The rocks from space initiative and the space safari

This paper reports the successes of a new initiative in the UK using electronic resources, such as virtual learning environments and e-classrooms, for planetary and space science public engagement activities

An evaluation methodology for ergonomic design of electronic consumer products based on fuzzy axiomatic design

This article is posted with permission of OCP Science imprint. Copyright @ 2008 Old City Publishing Group.The development life cycle of software and electronic products has been shortened by the growth of rapid prototyping techniques. The evaluation of electronic consumer products should consider hardware and software as well as the ergonomic usability, emotional appeal and aesthetic integrity of the design. This research follows a systematic approach to develop an evaluation methodology for electronic mobile products on ergonomic design. The proposed methodology is based on fuzzy multi attribute decision making and fuzzy axiomatic design realized in three steps; determination of ergonomic attributes for electronic consumer products, determination of a representative set of alternatives, and selection of the best alternative in terms of ergonomic design by utilizing fuzzy axiomatic design. A case study is also provided to support the proposed methodology