Fermi edge singularity in neutral electron-hole system

In neutral dense electron-hole (e-h) systems at low temperatures, theory predicts Cooper-pair-like excitons at the Fermi energy and a BCS-like exciton condensation. Optical excitation allows creating e-h systems with the densities controlled by the excitation power. However, the intense optical excitations required to achieve high densities cause substantial heating of the e-h system that prevents the realization of dense and cold e-h systems in conventional semiconductors. In this work, we study e-h systems created by optical excitation in separated electron and hole layers. The layer separation increases the e-h recombination time and, in turn, the density for a given optical excitation by orders of magnitude and, as a result, enables the realization of the dense and cold e-h system. We found a strong enhancement of photoluminescence intensity at the Fermi energy of the neutral dense ultracold e-h system that evidences the emergence of excitonic Fermi edge singularity due to the Cooper-pair-like excitons at the Fermi energy

A conceptual study of spirituality in selected writings of Emile Jaques-Dalcroze

Several authors have noted that one of Émile Jaques-Dalcroze’s aims was to dissolve the mind–body dualism, typical of Cartesianism. However, there has been little research on the spirit–body connection, as it appears in Jaques-Dalcroze’s writings. The purpose of this document analysis is to understand how a hermeneutic phenomenological model for spirituality in music education can inform our understanding of spirituality in selected writings by Jaques-Dalcroze. In the adapted model holism, balance, aesthetic experience, and movement in time, space, and with energy emerged as core concepts. This gives us a much richer understanding of the Dalcroze approach than has hitherto been available and adds to a growing narrative about the spiritual as it pertains to Jaques-Dalcroze and the approach he initiated

Catching-up in the global factory: analysis and policy implications

MNEs shape the location of activities in the world economy, linking diverse regions in what has been called the global factory. This study portrays the evolution of incomes and employment in the global factory using a quantitative input–output approach. We find emerging economies forging ahead relative to advanced economies in income derived from fabrication activities, handling the physical transformation process of goods. In contrast, convergence in income derived from knowledge-intensive activities carried out in pre- and post-fabrication stages is much slower. We discuss possible barriers to catching-up and policy implications for emerging economies in developing innovation capabilities, stressing the pivotal role of MNEs