Interlaboratory study on Sb2S3 interplay between structure, dielectric function, and morphous-to-crystalline phase change for photonics

Antimony sulfide, Sb2S3, is interesting as the phase-change material for applications requiring high transmission from the visible to telecom wavelengths, with its band gap tunable from 2.2 to 1.6 eV, depending on the amorphous and crystalline phase. Here we present results from an interlaboratory study on the interplay between the structural change and resulting optical contrast during the amorphous-to-crystalline transformation triggered both thermally and optically. By statistical analysis of Raman and ellipsometric spectroscopic data, we have identified two regimes of crystallization, namely 250_C % T < 300_C, resulting in Type-I spherulitic crystallization yielding an optical contrast Dn _ 0.4, and 300 % T < 350 _ C, yielding Type-II crystallization bended spherulitic structure with different dielectric function and optical contrast Dn _ 0.2 below 1.5 eV. Based on our findings, applications of on-chip reconfigurable nanophotonic phase modulators and of a reconfigurable high-refractive-index core/phase-change shell nanoantenna are designed and proposed.The authors acknowledge the support from the European Union’s Horizon 2020 research and innovation program (No 899598 - PHEMTRONICS)

Probing particle-phonon-coupled states in the neutron-rich nucleus Cu-65 by lifetime measurements with fast-timing techniques

The Cu-65 nucleuswas populated by the Ni-64(Li-7,alpha 2n)Cu-65 reaction and the lifetime of the 9/2(+) state at 2.5 MeV was measured by electronic fast-timing technique, providing the value tau = 37(3) ps. The reduced transition probability B(E3) = 8.82(165) W.u. is deduced and compared to theoretical predictions in the framework of a particle-vibration (weak) coupling model. The results indicate that the 9/2(+) state is a member of the 3(-)circle times pi p3/2 multiplet, built by coupling the octupole 3(-) phonon of Ni-64 to an unpaired proton in the p(3/2) level, confirming the robustness of core excitations in the medium mass nucleus Ni-64

Screening of magnetic fields by superconducting and hybrid shields with a circular cross-section

The use of superconducting (SC) materials is crucial for shielding quasi-static magnetic fields. However, the need for space-saving solutions with high shielding performance requires the development of a three-dimensional (3D) modelling procedure capable of predicting the screening properties for different orientations of the applied field. In this paper, we use a 3D numerical model based on a vector potential formulation to investigate the shielding ability of SC screens with cylindrical symmetry and a height/diameter aspect ratio close to unity, without and with the superimposition of a ferromagnetic (FM) circular shell. The chosen materials were MgB2 and soft iron. First, the outcomes of the calculations were compared with the experimental data obtained with different shielding arrangements, achieving a notable agreement in both axial field (AF) and transverse field (TF) orientations. Then, we used this validated modelling approach to investigate how the magnetic mitigation properties of a cup-shaped SC bulk can be improved by the superimposition of a coaxial FM cup. Calculations highlighted that the FM addition is very efficient in enhancing the shielding factors (SFs) in the TF orientation. Assuming a working temperature of 30 K and using a layout with the FM cup protruding over the SC one, SFs up to eight times greater than those with a single SC cup were attained at applied field up to 0.15 T, reaching values equal to or higher than 102 in the inner half of the shield. In the AF orientation, the addition of the same FM cup incurs a modest worsening at low fields, but at the same time it widens the applied field range where SF ⩾ 10^4 occurs near the close extremity of the shield to over 1 T

Formal Modelling of Reactive Agents as an Aggregation of Simple Behaviours

Abstract. Agents, as highly dynamic systems, are concerned with three essential factors: (i) a set of appropriate environmental stimuli, (ii) a set of internal states, and (iii) a set of rules that relates the previous two and determines what the agent state will change to if a particular stimulus arrives while the agent is in a particular state. Although agent-oriented software engineering aims to manage the inherent complexity of software systems, there is still no evidence to suggest that any proposed methodology leads towards correct systems. In the last few decades, there has been a strong debate on whether formal methods can achieve this goal. In this paper, we show how a formal method, namely X-machines, can deal successfully with agent modelling. The X-machine possesses all those characteristics that can lead towards the development of correct systems. X-machines are capable of modelling both the changes that appear in an agent&apos;s internal state as well as the structure of its internal data. In addition, communicating X-machines can model agents that are viewed as an aggregation of different behaviours. The approach is practical and disciplined in the sense that the designer can separately model the individual behaviours of an agent and then describe the way in which these communicate. The effectiveness of the approach is demonstrated through an example of a situated, behaviour-based agent.

Contribution of the 80s loop of HIV-1 protease to the multidrug-resistance mechanism: crystallographic study of MDR769 HIV-1 protease variants

Structural studies revealed a proline switch as a novel mechanism for the multidrug-resistant nature of multidrug-resistant clinical isolate 769 HIV-1 protease variants