Transform-limited photons from a coherent tin-vacancy spin in diamond

Solid-state quantum emitters that couple coherent optical transitions to long-lived spin qubits are essential for quantum networks. Here we report on the spin and optical properties of individual tin-vacancy (SnV) centers in diamond nanostructures. Through cryogenic magneto-optical and spin spectroscopy, we verify the inversion-symmetric electronic structure of the SnV, identify spin-conserving and spin-flipping transitions, characterize transition linewidths, measure electron spin lifetimes and evaluate the spin dephasing time. We find that the optical transitions are consistent with the radiative lifetime limit even in nanofabricated structures. The spin lifetime is phononlimited with an exponential temperature scaling leading to $T_1$ $>$ 10 ms, and the coherence time, $T_2$ reaches the nuclear spin-bath limit upon cooling to 2.9 K. These spin properties exceed those of other inversion-symmetric color centers for which similar values require millikelvin temperatures. With a combination of coherent optical transitions and long spin coherence without dilution refrigeration, the SnV is a promising candidate for feasable and scalable quantum networking applications

A variational joint segmentation and registration framework for multimodal images

Image segmentation and registration are closely related image processing techniques and often required as simultaneous tasks. In this work, we introduce an optimization-based approach to a joint registration and segmentation model for multimodal images deformation. The model combines an active contour variational term with mutual information (MI) smoothing fitting term and solves in this way the difficulties of simultaneously performed segmentation and registration models for multimodal images. This combination takes into account the image structure boundaries and the movement of the objects, leading in this way to a robust dynamic scheme that links the object boundaries information that changes over time. Comparison of our model with state of art shows that our method leads to more consistent registrations and accurate results

Change and continuity in Japanese compensation practices: the case of occupational pensions since the early 2000s

This article analyses changes in the provision of Japanese occupational pensions since the early 2000s. It shows how Japanese companies have followed strategies of cost and risk reduction by creating multi-layered benefit systems that offer a combination of defined benefit (DB) and defined contribution (DC) plans whose benefits are becoming increasingly performance-oriented. Analysing the reasons behind the resilience of DB schemes in Japan, the article concludes that enterprise union behaviour has had less influence than regulatory issues and continued corporate commitment to long-standing employment practices for regular workers. These findings highlight the embeddedness of Japanese employment practices in their institutional context

Globalization and CSR in Asia

Whether companies should exercise some ‘social responsibility’ beyond economic outcomes, and how they should go about doing so, has exercised scholars for more than 50 years. For the most part, prevailing perspectives have reflected the cultural norms and regulatory frameworks of North America and Europe. Interest beyond these contexts is a relatively recent – and still developing – body of scholarship. Undoubtedly, globalization is, in part, responsible for the emerging interest in CSR in Asia. Not only have moves toward greater economic integration ushered in new opportunities for businesses in Asia, but it has also raised a number of new challenges. Trade liberalization and economic reform have opened up new markets for labour and raw materials, generating unprecedented potential to produce wealth, but these developments have been accompanied by new concerns that also deserve close inquiry

Using 1-D Radar Observations to Detect a Space Explosion Core Among the Explosion Fragments

A radar observes the result of a space explosion. Due to radar’s low horizontal resolution, we get a 1-D signal x(t) representing different 2-D slices. Based on these slices, we must distinguish between the body at the core of the explosion and the slowly out-moving fragments. We propose new algorithms for processing this 1-D data. Since these algorithms are time-consuming, we also exploit the possibility of parallelizing these algorithms. 1. FORMULATION OF THE PROBLEM Most astronomical processes are slow; however, sometimes, space explosions happen: starts become supernovae, planetoids are torn apart by tidal and gravitational forces, etc. Even the Universe itself is currently viewed as a result of such an explosion – the Big Bang. From the astrophysical viewpoint, these explosions are very important, because, e.g., supernovae explosions is how heavy metals spread around in the Universe. The explosion processes are very rare and very fast, so unless they are very powerful and spectacular – like an explosion of a nearby supernovae that happened in 1054 – they are very difficult to observe. As a result, space explosion processes often go unnoticed. What we do observe in most cases is the result of the space explosion, i.e., the explosion core – the remainder of the original celestial body – surrounded by the explosion fragments. The most well known example of such a result is the Crab Nebula formed after the 1054 supernovae explosion

Rotary kiln technology: Progress report no 3

Abstract not available

Rotary kiln technology: Progress report no 1

Abstract not available