Quantum homogenization for continuous variables: Realization with linear optical elements

Recently Ziman et al. [Phys. Rev. A 65, 042105 (2002)] have introduced a concept of a universal quantum homogenizer which is a quantum machine that takes as input a given (system) qubit initially in an arbitrary state rho and a set of N reservoir qubits initially prepared in the state xi. The homogenizer realizes, in the limit sense, the transformation such that at the output each qubit is in an arbitrarily small neighborhood of the state xi irrespective of the initial states of the system and the reservoir qubits. In this paper we generalize the concept of quantum homogenization for qudits, that is, for d-dimensional quantum systems. We prove that the partial-swap operation induces a contractive map with the fixed point which is the original state of the reservoir. We propose an optical realization of the quantum homogenization for Gaussian states. We prove that an incoming state of a photon field is homogenized in an array of beam splitters. Using Simon's criterion, we study entanglement between outgoing beams from beam splitters. We derive an inseparability condition for a pair of output beams as a function of the degree of squeezing in input beams.

Electron collisions with iron peak elements: a computational grand challenge

This paper discusses the calculation of electron impact collision strengths and effective collision strengths for iron peak elements of importance in the analysis of many astronomical and laboratory spectra. It commences with a brief overview of R-matrix theory which is the basis of computer programs which have been widely used to calculate the relevant atomic data used in this analysis. A summary is then given of calculations carried out over the last 20 y for electron collisions with Fe II. The grand challenge, represented by the calculation of accurate collision strengths and effective collision strengths for this ion, is then discussed. A new parallel R-matrix program PRMAT, which is being developed to meet this challenge, is then described and results of recent calculations, using this program to determine optically forbidden transitions in e- – Ni IV on a Cray T3E-1200 parallel supercomputer, are presented. The implications of this e- – Ni IV calculation for the determination of accurate data from an isoelectronic e- – Fe II calculation are discussed and finally some future directions of research are reviewed.

The Cost of Sustainability Capital and the Creation of Sustainable Value by Companies

We develop and apply a valuation methodology to calculate the cost of sustainability capital, and, eventually, sustainable value creation of companies. Sustainable development posits that decisions must take into account all forms of capital rather than just economic capital. We develop a methodology that allows calculation of the costs that are associated with the use of different forms of capital. Our methodology borrows the idea from financial economics that the return on capital has to cover the cost of capital. Capital costs are determined as opportunity costs, that is, the forgone returns that would have been created by alternative investments. We apply and extend the logic of opportunity costs to the valuation not only of economic capital but also of other forms of capital. This allows (a) integrated analysis of use of different forms of capital based on a value-based aggregation of different forms of capital, (b) determination of the opportunity cost of a bundle of different forms of capital used in a company, called cost of sustainability capital, (c) calculation of sustainability efficiency of companies, and (d) calculation of sustainable value creation, that is, the value above the cost of sustainability capital. By expanding the well-established logic of the valuation of economic capital in financial markets to cover other forms of capital, we provide a methodology that allows determination of the most efficient allocation of sustainability capital for sustainable value creation in companies. We demonstrate the practicability of the methodology by the valuation of the sustainability performance of British Petroleum (BP).

The Sustainability Balanced Scorecard. Linking Sustainability Management to Business Strategy.

The Balanced Scorecard of Kaplan and Norton is a management tool that supports the successful implementation of corporate strategies. It has been discussed and considered widely in both practice and research. By linking operational and non-financial corporate activities with causal chains to the firm's long-term strategy, the Balanced Scorecard supports the alignment and management of all corporate activities according to their strategic relevance. The Balanced Scorecard makes it possible to take into account non-monetary strategic success factors that significantly impact the economic success of a business. The Balanced Scorecard is thus a promising starting-point to also incorporate environmental and social aspects into the main management system of a firm. Sustainability management with the Balanced Scorecard helps to overcome the shortcomings of conventional approaches to environmental and social management systems by integrating the three pillars of sustainability into a single and overarching strategic management tool. After a brief discussion of the different possible forms of a Sustainability Balanced Scorecard the article takes a closer look at the process and steps of formulating a Sustainability Balanced Scorecard for a business unit. Before doing so, the basic conventional approach of the Balanced Scorecard and its suitability for sustainability management will be outlined in brief.