Scientific Publications of the University of Toulouse II Le Mirail
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QE-CONVERSE: An open-source package for the quantum ESPRESSO distribution to compute non-perturbatively orbital magnetization from first principles, including NMR chemical shifts and EPR parameters
No full textInternational audienceOrbital magnetization, a key property arising from the orbital motion of electrons, plays a crucial role in determining the magnetic behavior of molecules and solids. Despite its straightforward calculation in finite systems, the computation in periodic systems poses challenges due to the ill-defined position operator and surface current contributions. The modern theory of orbital magnetization, formulated in the Wannier representation and implemented within the Density Functional Theory (DFT) framework, offers an accurate solution through the “converse approach.” In this paper, we introduce Image 1, a refactored and modular implementation of the converse method, designed to replace the outdated routines from Quantum ESPRESSO (version 3.2). Image 2 integrates recent advancements in computational libraries, including scaLAPACK and ELPA, to enhance scalability and computational efficiency, particularly for large supercell calculations. While Image 3 incorporates these improvements for scalability, the main focus of this work is provide the community with a performing and accurate first principles orbital magnetization package to compute properties such as Electron Paramagnetic Resonance (EPR) g-tensors and Nuclear Magnetic Resonance (NMR) chemical shifts, specially in systems where perturbative methods fail. We demonstrate the effectiveness of Image 4 through several benchmark cases, including the NMR chemical shift of 27Al in alumina and 17O and 29Si in α-quartz, as well as the EPR g-tensor of radicals and substitutional nitrogen defects in silicon. In all cases, the results show excellent agreement with theoretical and experimental data, with significant improvements in accuracy for EPR calculations over the linear response approach. The Image 5 package, fully compatible with the latest Quantum ESPRESSO versions, opens new possibilities for studying complex materials with enhanced precision
Fonctionnement et maintenance de l'installation d'eau déionisée (février 2026)
No full textNational audienceCe rapport présente le fonctionnement de l’installation d’eau déionisée de la plateforme de micro et nanotechnologies du LAAS-CNRS dans sa configuration depuis 2020
Les magiciens et magiciennes du monde gréco-romain: Pratiques, savoirs, représentations
No full textNational audienceContribution to the catalogue of the exhibition "Sorcières" (February 6-June 28 2026, Musée d'Histoire de Nantes).Contribution au catalogue de l'exposition "Sorcières" (6 février-28 juin 2026, Musée d'Histoire de Nantes)
Crouzeix-Raviart finite element approximation for elastoplastic torsion
No full textThis study is concerned with the elastoplastic torsion problem written in its weak form as a variational inequality in two space dimensions. We consider a Crouzeix-Raviart finite element approximation. We establish an optimal error bound of order h in the natural norm, for a regular enough continuous solution
AntFlie: Frugal Visual Teach and Repeat on Narrow FoV Micro-Drones
No full textInternational audienceWe present an insect-inspired visual teach-and-repeat framework demonstrated on Antflie, a 33-gram MAV equipped with an ultra-low-resolution camera (24×24 px) and a narrow 87° field of view (FoV). During a one-shot teach flight along an outbound route, the MAV performs periodic physical scans and uses a local compass based on inertial and optic flow cues to categorize views as left or right relative to the path, storing compact, lateralized visual memories in a Mushroom Body (MB) neural network with a footprint under 4 kB. In the repeat phase, the MAV flies the inbound route by retracing the outbound path, and autonomously lands at its home location using only visual familiarity through direct sensorimotor coupling, rather than map-based reasoning. Offline simulations show that the Route Lateralized (R-Lat) algorithm in Antflie matches the accuracy of a state-of-the-art insect visual compass (V-Comp) while running up to 20× faster and supporting narrow FoVs. Real-world indoor experiments further demonstrate 24 autonomous inbound repeats totaling 110 meters of flight, with a 13-cm median lateral error and a mean landing error of 34 cm. These results highlight the feasibility of frugal, bio-inspired, vision-only navigation for MAVs operating under strict size, weight, power, and cost constraints, inspired by the navigation of Cataglyphis and Melophorus ants
940-nm VCSELs grown by molecular beam epitaxy on Ge(001)
No full textInternational audienceVertical-cavity surface-emitting laser (VCSEL) structures emitting near 940 nm were grown by solid source molecular beam epitaxy (MBE) on Ge(001) substrates. The VCSEL MBE-growth was realized upon a virtual substrate composed of GaAs on Ge grown by melatorganic vapour phase epitaxy (MOVPE). In situ monitoring during MBE growth employed multispectral reflectometry and magnification-inferred curvature imaging for real-time growth analysis. Curvature measurements revealed progressive compressive stress, while optical reflectivity data confirmed uniform layer growth and accurate stopband formation. Fabricated devices with mesa diameters of 35-40 µm, corresponding to oxide apertures of approximately 11-16 µm, exhibited room-temperature lasing under continuous-wave bias with threshold currents below 3 mA. To the best of our knowledge, this is the first demonstration of monolithically integrated 940 nm VCSELs grown on Ge substrates by MBE. These results confirm the viability of MBE-grown VCSELs on Ge with in situ process control for scalable optoelectronic integration
Emotional Congruence in Childhood: The Influence of Music and Color on Cognitive Processing
No full textInternational audienceEmotions are known to influence cognitive processes, yet the nature of this influence remains debated, particularly during childhood. According to the emotional congruence model, information congruent with an individual’s affective state is processed more efficiently than incongruent information. While this effect has been widely studied in adults, evidence in children is still limited. The present research investigates the influence of emotional congruence on selective attention in typically developing children from preschool to fifth grade, using a dual emotional induction paradigm based on music and color. In Study 1, classical music excerpts were used to induce pleasant or unpleasant emotional states and to validate the effectiveness of musical induction across age groups. In Study 2, this musical induction was combined with emotionally valenced color cues (yellow vs. gray) embedded in a visual search task to examine their impact on attentional performance. Results from Study 1 confirmed that music effectively modulated children’s emotional valence, although this effect was weaker in younger participants. In Study 2, attentional performance improved significantly when the task was presented on a yellow background, regardless of the valence of the previously induced musical emotion. No robust emotional congruence effect between music and color was observed, although performance was highest in the joyful music–yellow color condition. Overall, these findings suggest that perceptual emotional cues embedded in the task context, particularly positive color cues, exert a stronger and more persistent influence on children’s selective attention than transient affective states induced by music. This study contributes to developmental models of emotion–cognition interaction by highlighting asymmetrical valence effects and the predominant role of perceptual emotional signals in childhood attention
Swarm dynamics for global optimisation on finite sets
No full textInternational audienceConsider the global optimisation of a function defined on a finite set endowed with an irreducible and reversible Markov generator.By integration, we extend to the set of probability distributions on and we penalise it with a time-dependent generalised entropy functional.Endowing with a Maas' Wasserstein-type Riemannian structure, enables us to consider an associated time-inhomogeneous gradient descent algorithm.There are several ways to interpret this \cP(V)-valued dynamical system as the time-marginal laws of a time-inhomogeneous non-linear Markov process taking values in , each of them allowing for interacting particle approximations.This procedure extends to the discrete framework the continuous state space swarm algorithm approach of Bolte, Miclo and Villeneuve \cite{Bolte}, but here we go further by considering more general generalised entropy functionals for which functional inequalities can be proven.Thus in the full generality of the above finite framework, we give conditions on the underlying time dependence ensuring the convergence of the algorithm toward laws supported by the set of global minima of .Numerical simulations illustrate that one has to be careful about the choice of the time-inhomogeneous non-linear Markov process interpretation
skwdro: a library for Wasserstein distributionally robust machine learning
No full textInternational audienceWe present skwdro, a Python library for training robust machine learning models. The library is based on distributionally robust optimization using optimal transport distances. For ease of use, it features both scikit-learn compatible estimators for popular objectives, as well as a wrapper for PyTorch modules, enabling researchers and practitioners to use it in a wide range of models with minimal code changes. Its implementation relies on an entropic smoothing of the original robust objective in order to ensure maximal model flexibility. The library is available at this URL https://github.com/iutzeler/skwdr
What are we to each other? The limits of DNA in the search for origins in donor conception
No full textInternational audienceFor decades, third-party reproduction was shrouded in secrecy, and gamete donation was anonymous in most countries. This situation was however challenged by the increased attention to the harmful effects of family secrets and by the claims of donor-conceived people seeking access to their origins. The rise of direct-to-consumer (DTC) DNA testing further transformed the landscape of donor conception, leading some individuals to unexpectedly discover their donor conception, and others to bypass anonymity rules. In the social sciences, origins have sparked new questions, shedding light on the meanings attributed to procreation and relatedness. The search for origins has been analysed either as reinforcing essentialist views of kinship and identity or as part of a relational, temporal and narrative process. Yet, little is known about how donor-conceived people actually navigate this search. Drawing on an ethnographic study with French and English sperm donor-conceived adults, this chapter examines how they use DTC DNA testing to explore their origins. It documents their investigative methods and interpretative techniques, and highlights both the insights and the limitation of DNA and the epistemological framework employed by genetic genealogy websites to produce knowledge about origins in donor conception