SFP Alpes

Kilian FRABOULET (Max Planck Institute Stuttgart)
2026-03-06 11:00 - 12:00 (Europe/Paris) | LPMMC – salle Roger Maynard (G421), CNRS - LPMMC 25 avenue des Martyrs, Grenoble, 38042, France
Competing orders in many-electron systems: a renormalization group perspective
Résumé :
The renormalization group is an established approach to study quantum many-body systems, and this applies especially to one of its modern implementations known as the functional renormalization group (fRG). In particular, the fRG constitutes a flexible and unbiased tool for the study of competing orders. In this talk, I will outline recent progress in this direction for correlated electron systems. To this end, I will first discuss the competition between antiferromagnetism, charge density waves and superconductivity in the 2D Hubbard model, thus making a connection with high-temperature superconductors. The special role of bosonization methods will be emphasized along the way. I will also show how the fRG can be combined with dynamical mean-field theory to treat strongly interacting regimes, with a focus on d-wave superconductivity. As a next step, I will increase the complexity of the model by including non-local interactions and discuss unconventional superconductivity in an extended Hubbard model with a connection to moiré materials. Special consideration will also be given to the treatment of retarded interactions with electron-phonon couplings. Finally, I will highlight recent fRG studies of quantum criticality in Dirac materials, with a connection to graphene.
Contact : serge.florens@neel.cnrs.fr

Carlo PIFFERI (Centre de Biophysique Moléculaire, Orléans)
2026-03-06 14:00 - 15:00 | DCM – Salle C209, DCM - Bât Chimie Recherche 301 rue de la Chimie, St Martin d'Hères, 38400, France
Exploiting disulfide-rich peptides as protein epitope mimics : development of a generalizable conjugation approach for immunogen preparation
Résumé :
Generation of specific antibodies against peptides by immunization requires their covalent conjugation to protein carriers to override their inherently weak immunogenicity. The vast majority of bioconjugation approaches to achieve peptide-protein constructs rely on thiol-maleimide chemistry1 and capitalize on a wide array of commercial maleimide-functionalized protein carriers. Disulfide-rich peptides2 (DRPs) possess a rigid, constrained structure that makes them ideal for designing synthetic mimics of protein regions/domains. For bioconjugation purposes, the introduction of a single spare thiol moiety into a linear peptide antigen is straightforward, while DRPs’ disulfide bonds are prone to intramolecular thiophilic attack by the reactive thiolate. This unintended reactivity competes with the desired Michael addition to the maleimide moiety, ultimately disrupting the native disulfide bridging framework. As a result, DRP’s tertiary structure will be altered, affording an immunogen that is a poor mimic of the native target. Although a few studies have explored the late-stage introduction of thiol-containing cross-linkers onto DRP antigens for their conjugation onto protein carriers,3,4 the stability of DRP’s disulfide pattern in the presence of an extra thiol has never been examined. To address this, we systematically evaluated the influence of different spacers in “DRP-spacer-thiol” constructs, under thiol-maleimide reaction conditions.5 Our results highlight how both linker length and flexibility are key to maintain DRP disulfides unaltered, providing a general approach to achieve DRP bioconjugation by thiol-maleimide chemistry. We have applied our approach to a small DRP predicted to closely mimic a surface-accessible epitope of the full LINGO-1 protein, and obtained a very specific antibody response upon immunization: the resulting polyclonal IgG was able to selectively bind the full-length protein in a cellular context, with stringent selectivity across its four homologs.
References :
1. M. Góngora-Benítez, J. Tulla-Puche & F. Albericio, Chem. Rev. 2014, 114, 901–926.
2. K. Renault, J. W. Fredy, P.-Y. Renard & C. Sabot, Bioconjug. Chem. 2018, 29, 2497–2513.
3. H. Katayama & M. Mita, Bioorganic Med. Chem. 2016, 24, 3596–3602.
4. H. Katayama, R. Mizuno & M. Mita, Biosci. Biotechnol. Biochem. 2019, 83, 1791–1799.
5. L. Azzoug et al., ChemRxiv 2025, DOI:10.26434/chemrxiv-2025-krjcm
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Contact : david.goyard@univ-grenoble-alpes.fr

Marek BARTKOWIAK (Paul Scherrer Institut)
2026-03-09 14:00 - 15:00 | CNRS – Salle Louis Weil (E424), CNRS - Institut Néel 25 avenue des Martyrs, Grenoble, 38042, France
Spin-orbit control of antiferromagnetic domains without a Zeeman coupling
Résumé :
Encoding information in antiferromagnetic (AFM) domains is a promising solution for the ever growing demand in magnetic storage capacity. The absence of a macroscopic magnetization avoids crosstalk between different domain states, enabling ultrahigh density spintronics while being detrimental to the domain detection and manipulation. Disentangling these merits and disadvantages seemed so far unattainable. We report evidence for a new AFM domain selection mechanism based on non Zeeman susceptibility anisotropy induced by the relative orientation of external magnetic fields to the k-domains. Consequently, the charge transport response is controlled by the rotation of the magnetic field and a pronounced anisotropic magnetoresistance is found in the AFM phase of bulk materials Nd$_{1−x}$Ce$_x$xCoIn$_5$. Our results and the domain switching theory indicate that this constitutes a new effect which might be universal across multiband materials. It provides a novel mechanism to control and detect AFM domains, opening new perspectives for AFM sprintronics.
Contact : andrew.fefferman@neel.cnrs.fr

Synergies in High Resolution Spectroscopy workshop (HIRES2026)
2026-03-10 00:00 - 2026-03-13 23:59 | ILL – Salle de Séminaire (SB-036), ILL 71 avenue des Martyrs, Grenoble, 38042, France
The workshop will bring together researchers in the fields of neutron spin-echo, backscattering, and time-of-flight (TOF) spectroscopy. It aims to highlight the strengths and synergies of these techniques, while also showcasing their interplay with other non-neutron-based methods.
Participation is not limited to neutron experts, users of complementary techniques who wish to expand their research toward neutron scattering are also warmly welcome.
Abstract submission deadline is 30 November 2025.
For full details please visit the website of the workshop: https://workshops.ill.fr/e/HIRES2026

If you have any questions don’t hesitate to contact the Organising Committee by e-mailing to hires@ill.fr

Synergies in High Resolution Spectroscopy workshop (HIRES2026)
2026-03-10 08:30 - 2026-03-13 12:00 | ILL 4, Grenoble, 38000, France
The workshop will bring together researchers in the fields of neutron spin-echo, backscattering, and time-of-flight (TOF) spectroscopy. It aims to highlight the strengths and synergies of these techniques, while also showcasing their interplay with other non-neutron-based methods.
Participation is not limited to neutron experts, users of complementary techniques who wish to expand their research toward neutron scattering are also warmly welcome.
For full details please visit the website of the workshop : https://workshops.ill.fr/e/HIRES2026
If you have any questions don’t hesitate to contact the Organising Committee by e-mailing to hires@ill.fr
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Contact : HIRES2026@ill.fr

François PARMENTIER (Laboratoire de physique de l'école normale supérieure)
2026-03-10 14:00 - 15:00 | CNRS – Salle Rémy Lemaire (K223), CNRS - Institut Néel 25 avenue des Martyrs, Grenoble, 38042, France
Quantized heat flow in the Hofstadter butterfly
Résumé :
When subjected to a strong magnetic field, electrons on a two-dimensional lattice acquire a fractal energy spectrum called Hofstadter’s butterfly. In addition to its unique recursive structure, the Hofstadter butterfly is intimately linked to non-trivial topological orders, hosting a cascade of ground states characterized by non-zero topological invariants. These states, called Chern insulators, are usually understood as replicas of the ground states of the quantum Hall effect, with electrical and thermal conductances that should be quantized, reflecting their topological order. The Hofstadter butterfly is now commonly observed in van-der-Waals heterostructures-based moiré superlattices. However, its thermal properties, particularly the quantized heat flow expected in the Chern insulators, have not been investigated, potentially questioning their similarity with standard quantum Hall states. Here we probe the heat transport properties of the Hofstadter butterfly, obtained in a graphene / hexagonal boron nitride moiré superlattice. We observe a quantized heat flow, uniquely set by the topological invariant, for all investigated states of the Hofstadter butterfly: quantum Hall states, Chern insulators, and even symmetry-broken Chern insulators emerging from strong electronic interactions. Our work firmly establishes the universality of the quantization of heat transport and its intimate link with topology. A. Zhang, et al., arXiv:2601.05694 (2026)
Contact : equipe-seminaires-nano@listes.grenoble.cnrs.fr

Tymoteusz TULA (LPMMC, CNRS, Grenoble)
2026-03-11 11:00 - 12:00 | LPMMC – salle Roger Maynard (G421), CNRS - LPMMC 25 avenue des Martyrs, Grenoble, 38042, France
One-to-one correspondence between two-point correlators and entanglement in magnetic systems
Résumé :
There are multiple measures of multipartite entanglement — including entanglement in thermal mixtures — currently used to study many-body interacting systems. Recently, Quantum Fisher Information has been proposed as a multipartite entanglement measure that can be connected to experimentally accessible observables. In this talk, I will present our recent findings about a one-to-one correspondence between two-point correlators and a certain general class of Heisenberg-like Hamiltonians and wavefunctions. This is a foundation of our claim that a mapping from finite-temperature observables to any entanglement measure exists for such systems. Furthermore, I will present our results of training a convolutional neural network (CNN) to recognize and predict the entanglement for one-dimensional anisotropic XY and XYZ models, which exhibit an entanglement transition. From our preliminary results we found that entanglement can be accurately predicted by a CNN using both static and dynamical correlators, even when the network is trained on only a fraction of the full dataset or on data from a different system than the one used for prediction. Specifically, when trained on observables from an anisotropic XY model, accurate predictions can be achieved using only about 3% (6%) of the data when employing dynamical two-point correlators (structure factors) for learning.
Contact : pierre.nataf@lpmmc.cnrs.fr

Soutenance de Thèse de Subham SENAPATI (IRIG / Spintec)
2026-03-11 14:00 - 16:00 | CEA – Salle de Séminaire IRIG (1005 – 445), Laboratoire Irig/Spintec, salle de séminaire 445, bâtiment 1005, CEA-Grenoble, Grenoble
Spin-orbit torque based magnetic memories evaluation for cryogenic applications
Résumé :
The rapid development of cryogenic computing platforms, including superconducting electronics, quantum information processors, high-performance computing systems, and space applications, has created a demand for memory technologies that operate efficiently, reliably, and scalable at low temperatures. While magnetic random-access memory (MRAM) is a mature and commercially deployed non-volatile memory at room temperature, its behaviour and limitations at cryogenic temperatures remain insufficiently explored, particularly for three-terminal spin-orbit torque magnetic tunnel junctions (SOT-MTJs). This thesis presents a comprehensive experimental and modelling study of SOT-based magnetic memories operated from room temperature (300 K) down to liquid-helium (4 K) temperatures. A dedicated cryogenic characterisation framework is developed to extract magnetic parameters, quantify switching statistics, and evaluate write performance under both quasi-static and sub-nanosecond pulsed conditions. Temperature-dependent measurements reveal enhanced magnetic anisotropy and thermal stability at low temperatures, accompanied by non-trivial trends in critical switching current. By combining experiments with micromagnetic simulations incorporating temperature-dependent material properties and transient Joule heating, this work demonstrates that self-heating remains a dominant factor during write operations, especially at cryogenic bath temperatures. Beyond conventional SOT-MRAM, complementary approaches including optimised spin-transfer torque devices and voltage-gate-assisted SOT switching are investigated. They show that controlling retention via storage layer thickness is a relevant strategy to decrease write current while electric-field control of anisotropy enables efficient modulation of switching across a large temperature range. Overall, this thesis establishes both the physical limitations and technological potential of SOT- and voltage-gated SOT-based MRAM as viable candidates for future cryogenic memory systems.
https://www.cea.fr/drf/irig/Pages/Animation-scientifique/theses/2026_Senapati.aspx
Contact : admin.spintec@cea.fr

Alban DEROUX (médecine interne, cytopénies auto-immunes de l'adulte (CERECAI))
2026-03-12 08:00 - 09:00 | CHU – Salle Gilbert Faure, CHU Grenoble Alpes Pavillon Vercors (côté Belledonne), La Tronche, 38043, France
Thrombopénie : et si c’était un problème d’anticorps ? Comprendre le PTI
Contact : sante-communication@univ-grenoble-alpes.fr

Stéphane GUINDON (LIRMM - Montpellier)
2026-03-12 13:00 - 14:00 | IMAG – Salle de Réunion, 150 place du Torrent, St Martin d’Hères, 38400, France
Recent advances in phylogeography
Contact : lucie.lamothe@univ-grenoble-alpes.fr

Hugues Nury (Irig / IBS)
2026-03-12 18:30 - 22:30 | La Casemate, 2 Place Saint-Laurent, Grenoble, 38000, France
« Soirée du vivant » : récepteurs neuronaux : comment les poisons trouvent leur cible
Cette « S​​oirée du vivant », d’un format inédit, proposera présentation interactive, quiz participatifs, échanges libres, le tout autour de tapas végétales, pour un moment convivial et grand public.
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Hugues Nury, chercheur CNRS à l’Institut de biologie structurale de Grenoble, nous plongera dans l’univers fascinant des venins de serpents, alcaloïdes végétaux et autres insecticides modernes, qui exercent leurs effets en ciblant des récepteurs neuronaux spécifiques. Il apportera d’abord des connaissances générales pour répondre à des questions essentielles telles : pourquoi certaines substances sont-elles mortelles à des doses infimes tandis que d’autres restent inoffensives ? Comment un récepteur neuronal reconnaît-il son « poison » ?​​​​
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​Il présentera ensuite le projet ANR Pesti Penta qu’il coordonne, et qui vise à comprendre les mécanismes moléculaires d’action des insecticides sur les récepteurs neuronaux d’insectes. Cette recherche combine biologie structurale, dynamique moléculaire et électrophysiologie afin d’explorer les interactions entre différentes molécules et leurs cibles biologiques.
À terme, l’objectif de ces travaux fondamentaux est de contribuer au développement d’insecticides plus efficaces et plus ciblés.
En savoir plus : https://www.cea.fr/drf/irig/Pages/Animation-scientifique/seminaires/2026_Nury.aspx

Peter DAHLBERG (Stanford University, USA)
2026-03-13 11:00 - 12:00 | IBS – Salle des séminaires, IBS 71 avenue des Martyrs, Grenoble, 38042, France
Fluorescence-guided cryogenic FIB milling and their application to the study of the NLRP3 inflammasome
Résumé :
Numerous critical events in cell biology depend on rare ( 1 copy per cell) and small (<500 nm in diameter) structures. Observation of these processes at high resolution using cryogenic electron tomography (CryoET) presents challenges, as the structures must first be precisely targeted within thin sections through focused ion beam milling. In this presentation, I will introduce my group’s work on a tri-coincident system that integrates light, ion, and electron microscopy at a single focal point. This approach enables real-time monitoring of the milling process and makes two different modes of guidance possible that require no addition of fluorescent fiducials or image registration and whose accuracy far exceeds the optical diffraction limit. I will discuss both guidance modes in detail and then describe their application to the study of the in situ structure of the NLRP3 inflammasome. Despite its central role in innate immunity as a master regulator responsible for proinflammatory cytokine maturation and cell death, its in situ structure has remained elusive due to challenges in capturing the small singular punctum it forms per cell in thin sections compatible with CryoET — precisely the kind of target the tri-coincident system was developed for. Using our guidance approach, our cryo-tomograms revealed that the NLRP3 inflammasome forms a dense condensate within and around the microtubule-organizing center. At a later stage after activation, we saw further growth of the condensate, and the cells underwent pyroptosis with widespread mitochondrial damage and autophagy. Our study revealed new insights into NLRP3 structure and other organelle alterations during inflammation.
Contact : ibs.seminaires@ibs.fr

Grenoble Neurotech School 2026
2026-03-15 00:00 - 2026-03-20 23:59 | Centre Paul Langevin, Aussois, France
Plus d’informations : https://neurotech2026.sciencesconf.org/?lang=en

Contact : salma.mezzi@univ-grenoble-alpes.fr

Martha MERROW (LMU Munich, Germany)
2026-03-16 11:00 - 12:00 | LiPhy, Salle de Conférence, 140 rue de la Physique, St Martin d'Hères, 38400
A circadian clock in Bacillus subtilis
Résumé :
The circadian clock is a molecular machine that is present in each one of our cells, directing diverse processes in a cell(developmentally)-specific manner. The natural state of the clock is ‘entrainment’, namely through synchronization with zeitgeber signals (such as the light/dark cycle) in the environment. Once moved to constant conditions, a free running rhythm of approximately 24h can be observed, demonstrating the endogenous nature of the clock. One can understand how the clock relates to our lives by noting the timing of the sleep wake cycle: this is determined by the interaction of the biological (circadian) oscillator and the external zeitgeber cycle. Disrupting the clock in humans and mice leads to increased cancers, metabolic disease and decreased cognitive performance, likely through misexpression of key regulators. The circadian clock is an essential aspect of biology and its function can be regarded as a biophysical phenomenon.
Circadian clocks have been described in all kingdoms of life except for the Eubacteria – until very recently. I will discuss the circadian clock in the model prokaryote, Bacillus subtilis. We observe rhythms in gene expression, in colony morphology on agar, and in metabolism and in planktonic cultures. The circadian transcriptome shows pervasive regulation of gene expression by the biological clock, even more extensively than sigma factors. The clock is thus a major regulatory phenomenon in this bacterium. Our work begs the questions ‘what is the same as clocks in higher organisms?’ and ‘what is different?’.
Contact : irina.mihalcescu@univ-grenoble-alpes.fr

Montserrat SOLER-LÓPEZ (Macromolecular X-ray Crystallography, Imaging and Scattering Group, ESRF)
2026-03-17 14:00 - 15:00 | LMGP – salle des séminaires, Grenoble INP -Phelma 3 parvis Louis Néel, Grenoble, 38054, France
Mitochondrial Bioenergetics in Alzheimer’s Disease : Insights from the European Synchrotron
Résumé :

Alzheimer’s disease (AD) is a devastating neurodegenerative disorder increasingly linked to defects in mitochondrial bioenergetics. At the European Synchrotron Radiation Facility (ESRF), we investigate the structural and functional mechanisms that underlie mitochondrial dysfunction in AD, with a focus on respiratory complex I, a central player in cellular energy production [1,2].
Using an integrative biology approach, we combine macromolecular crystallography, cryo-electron microscopy, X-ray imaging, and spectroscopy to analyse the architecture and regulation of mitochondrial complex I and its assembly factors (MCIA proteins) across spatial and temporal scales. Our structural and functional studies reveal novel regulatory mechanisms of energy metabolism, including phosphorylation-dependent modulation at the interface of respiration and fatty acid oxidation. Importantly, we demonstrate that AD-related amyloid oligomers disrupt these regulatory processes within neuronal mitochondria, thereby contributing to oxidative stress and impaired bioenergetics in AD [3,4]. Recent synchrotron-based imaging, including X-ray fluorescence and nano-tomography, has further provided first insights into the ultrastructure of mitochondrial assemblies in situ.
Collectively, these findings highlight how the ESRF’s interdisciplinary, state-of-the-art methodologies enable breakthroughs in deciphering the molecular basis of neurodegeneration, offering new perspectives for diagnostic markers and therapeutic strategies targeting mitochondrial dysfunction in Alzheimer’s disease.
[1] Giachin et al. Dynamics of Human Mitochondrial Complex I Assembly: Implications for Neurodegenerative Diseases. Front. Mol. Biosci. 2016, 3:43
[2] McGregor & Soler-Lopez. Structural basis of bioenergetic protein complexes in Alzheimer’s disease pathogenesis. Cur Opin Struct Biol. 2023, 80:102573
[3] Giachin et al. Assembly of The Mitochondrial Complex I Assembly Complex Suggests a Regulatory Role for Deflavination. Angew. Chem. Int. Ed. 2021, 60(9):4689
[4] McGregor et al. The assembly of the Mitochondrial Complex I Assembly complex uncovers a redox pathway coordination. Nat Commun. 2023, 14(1):8248
Contact : deborah.verger@grenoble-inp.fr

Klaus MØLMER (Niels Bohr Institute, University of Copenhagen)
2026-03-17 14:00 - 15:00 | CNRS – Salle René Pauthenet (J229), CNRS – LNCMI, 25 avenue des Martyrs, Grenoble, 38000, France
Quantum optics with radiation on the move
Résumé :
With the scaling of quantum technologies to many separate material quantum components, we may have to couple these systems by propagating quantum radiation, in the form of light, microwaves or phonons. There are, however, rather fundamental obstacles to the treatment of propagation of quantum radiation and its interaction with matter. These obstacles include the general multimode character of propagating fields and the duration and spatial extent of useful light and microwave pulses. The talk will review a recent theoretical approach to deal theoretically with these obstacles, and it will present examples of new, unforeseen, possibilities for easy preparation and manipulation “on the fly” of quantum states of light and matter.
Coffee and croissants will be offered after the colloquium in front of the room !
Personne à contacter : Michele Filippone (michele.filippone@cea.fr)

Matthieu RAYNAL (Sorbonne Université, CNRS, Institut Parisien de Chimie Moléculaire (IPCM))
2026-03-19 14:00 - 15:00 | DCM – Salle C209, DCM - Bât Chimie Recherche 301 rue de la Chimie, St Martin d'Hères, 38400, France
Supramolecular helical catalysts : chirality induction and beyond
Résumé :
Helices are commonly formed by symmetry breaking operating during the bottom-up assembly of small molecules or monomers and their sense of rotation can be controlled by various methods. Important progress has been made in controlling the chiral and structural properties of supramolecular discrete assemblies and polymers.[1] Benzene-1,3,5- tricarboxamide[2] (BTA) are ubiquitous synthons for the preparation of hydrogen-bonded helices but it remains to be demonstrated how a given macroscopic property, notably related to chirality (e.g. chiroptical, magnetic, catalytic), can be affected by tuning the structure of these supramolecular polymers or copolymers. We demonstrated that the supramolecular chirality of BTA assemblies can be transferred to intrinsically achiral metal centres (Rh, Cu) located at their periphery.[3] How the selectivity of a catalytic reaction of reference can be affected by the nature of the monomers, the presence of metal centres, and the addition of achiral additives will be particularly discussed.[4] Not only a fine tuning of the chirality of the supramolecular assemblies but also a proper control of their dynamicity is key to address important challenges. We recently disclose the possibility to select one major (70%-79%) amongst four possible stereoisomers of an amino alcohol by applying the supramolecular helical catalyst in either concomitant (with no inversion of catalyst handedness) or sequential (with inversion of catalyst handedness) hydrosilylation and hydroamination reactions [5].
References :
[1] Yashima E. et al. Chem. Rev., 2016, 116, 13752.
[2] Cantekin S. et al. Chem. Soc. Rev., 2012, 41, 6125.
[3] Desmarchelier A. et al. J. Am. Chem. Soc., 2016, 138, 4908.
[4] (a) Li Y. et al. J. Am. Chem Soc., 2020, 142, 5676. (b) Martínez-Aguirre M. A. et al. Angew. Chem. Int. Ed., 2021, 60, 4183. (c) Hammoud A. et al. Chem. Eur. J., 2023, e202300189. (d) Kong H. et al. ChemistryEurope, 2023, 1, e202300027.
[5] Chen, R. et al. Nature Commun., 2024, 15, 4116
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Contact : adrien.quintard@univ-grenoble-alpes.fr

Rebeca RIBEIRO (C2N, Paris-Saclay)
2026-03-19 14:00 - 15:00 | CNRS – Salle Rémy Lemaire (K223), CNRS - Institut Néel 25 avenue des Martyrs, Grenoble, 38042, France
Twist-Angle-Controlled Anomalous Gating in Bilayer Graphene/BN Heterostructures
Résumé :
Anomalous gating effects—such as gate ineffectiveness and pronounced hysteresis—have been observed in graphene-based systems encapsulated in boron nitride (BN) and linked to a possible ferroelectric state. However, their origin, stability, and reproducibility remain under debate. During this talk, I will present charge transport experiments in dual-gated, dynamically rotatable van der Waals heterostructures based on bilayer graphene encapsulated in BN. Remarkably, the angular degree of freedom acts as an ON/OFF switch for the anomalous gating response. We show that the angular alignment between the two BN layers is the key parameter governing these effects. Both gate ineffectiveness and hysteresis are highly sensitive to small angular changes, and they clearly change in behavior, which we classify into three distinct regimes.
Contact : florence.levy-bertrand@neel.cnrs.fr

Chrystel GENOUD (EPFL, Lausane, Suisse)
2026-03-20 11:00 - 12:00 | IBS – Salle des séminaires, IBS 71 avenue des Martyrs, Grenoble, 38042, France
Understanding tissue by volumeEM – some examples from an EM platform
Séminaire dans le cadre de la Journée Microscopie Electronique
Résumé :
Understanding the complex architecture of cells and tissues requires imaging technologies that can bridge the gap between ultrastructural details and large-volume context in room temperature and cryo-EM. Volume electron microscopy (volume EM) addresses this need by enabling 3D imaging of biological samples at nanometer resolution over tens to hundreds of microns. In this presentation, I will provide an overview of volume EM techniques available on our platform based on examples and how we combine it with correlative light and electron microscopy.I will also show how we are adressing the targeting of small structures in lare tissue in cryo-ET by using the serial lift-out method and cryo-CLEM. The example of targeting the Casparian strip in the root of Arabidopsis thaliana will be developed.
Contact : ibs.seminaires@ibs

Pascal BOUSSEMART (Expert IA Générative (Orange Recherche Grenoble))
2026-03-20 12:30 - 13:15 | Amphi Minatec, 3 parvis Louis Néel, Grenoble, 38054, France
L’IA au coeur du travail
Résumé :
On parle beaucoup d’intelligence artificielle dans l’entreprise. Trop souvent comme d’un outil. Parfois comme d’une menace. Rarement comme d’un déplacement profond du rôle de l’employé, du manager et de l’organisation elle‑même.
À partir d’exemples concrets vécus (interaction réelle avec une IA, arbitrages humains, conflits de sens, décisions managériales), la conférence explore : l’impact de l’IA sur le métier, l’autonomie, la responsabilité et la reconnaissance et aussi comment l’entreprise doit se reconfigurer.
Il ne s’agit pas de dire si l’IA est « bonne » ou « mauvaise ». Il s’agit de comprendre ce que devient l’employé quand penser, décider, écrire, analyser ne lui appartiennent plus totalement.
Une conférence pour dirigeants, managers, chercheurs et salariés qui refusent les discours simplistes, et veulent explorer ce choc discret mais radical qui est en cours dans le monde du travail.
À propos des intervenants :
Pascal BOUSSEMART est expert en Intelligence Artificielle Générative et Formateur en Prompt Engineering chez Orange Recherche Grenoble.
Ingénieur diplômé Mines-Telecom, il cumule plus de 30 ans d’expérience dans l’innovation technologique. Véritable pionnier de l’IA générative, Pascal est l’auteur de plusieurs brevets dans ce domaine très innovant et il a participé au dépôt des projets coopératifs de recherche européens dont le dernier en 2025 sur l’impact des IA en entreprise. Il est également le créateur et animateur du
« Papotage IA Gen » chez Orange, un espace hebdomadaire dédié au partage et à la veille sur les usages de ces technologies.
Contact : giant.campus@cea.fr

ATTENTION !!! Séminaire reporté. Initialement prévu le 30 mars !!! - Bjoern WEHINGER (ESRF)
2026-03-20 13:30 - 14:30 | ILL – Salle de Séminaire (110-111), ILL 50 71 avenue des Martyrs, Grenoble, 38042, France
Neutron and x-rays scattering on quantum magnets at high pressures and low temperatures
Résumé :
Application of external pressure acts as clean tuning parameter of inter-atomic distances and bond angles and therefor allows for precise control of magnetic interactions in condensed matter. Extreme conditions can thus be used to stabilize novel quantum phases and drive systems close to quantum criticality where new and exciting phenomena are expected. Within this seminar I will show how recent advances in neutron and x-ray scattering allows to access fingerprints of quantum correlations and present novel results on quantum magnets at the extreme.
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Arno Hiezz (College 4 Secretary)
External visitors may ask for a site access to tellier(at)ill.fr

Chloé ROFFAY (IMP Vienna, Austria)
2026-03-23 11:00 - 12:00 | LiPhy – Salle de conférence, LiPhy 140 avenue de la Physique, St Martin d'Hères, 38402, France
Uncovering the forces driving the fate and shape of the extraembryonic amnion during human gastrulation
Résumé :
Extraembryonic tissues provide key molecular signals and mechanical support to the growing embryo. For instance, the extraembryonic amnion, which forms a fluid-filled sac surrounding the embryo, was recently shown to trigger germ layer specification during gastrulation, by secreting BMP ligands. Despite the key roles of extraembryonic tissues in embryo development, little is still known regarding their molecular and biophysical programs, particularly in human. Using a 2D stem cell-based model of human gastrulation, termed gastruloid discs, we found that amnion cells undergo a sharp columnar-to-squamous transition concomitantly with fate specification. Via biophysical modelling, direct force measurements, pharmacological and genetic perturbations, we showed that this morphogenetic transition is amnion-intrinsic and it is driven by active wetting, i.e. a transition from tensile to adhesion-dominated cellular states. Molecularly, active wetting is implemented via a rewiring of cytoskeleton composition, from actomyosin to keratin-based cytoskeletal networks, akin to a bistable toggle-switch in gene regulatory networks. Strikingly, blocking shape changes at the colony edge results both in defective cellular states in the amnion and impaired gastruloid disc morphogenesis within the embryonic compartment. Together, our findings establish that a cytoskeletal toggle switch couples fate specification to tissue architecture in the human amnion and suggest an unexpectedly active mechanical role for extraembryonic tissues in shaping the embryo proper.
Contact : thomas.boudou@univ-grenoble-alpes.fr

Stéphanie ROCCIA (LPSC-CNRS/UGA, GRENOBLE)
2026-03-23 14:00 - 15:00 | ILL – Salle de Séminaire (110-111), ILL 50 71 avenue des Martyrs, Grenoble, 38042, France
The search for neutron electric dipole moment at PSI
Résumé :
The Universe and its history are simultaneously very well understood and still a big mystery. We have amazing tools from satellites to
observatories to weight the universe over its history. But the components of the Universe can simply not yet be explained by physicists. To get the full picture, we need to identify and understand the interactions at play throughout the life of the Universe. This is the meeting point between particle physics and cosmology. At this meeting point stands the neutron, a common particle that we can uniquely use in high precision experiments.
I will present how experiments searching for a permanent electric dipole moment of the neutron (nEDM) aim at discovering new sources of CP violation beyond the Standard Model of particle physics and understanding the origin of the matter-antimatter asymmetry of the Universe. The quest for the neutron electric dipole moment started more than sixty years ago. In recent experiments, polarized ultra-cold neutrons are stored in material bottles.
I will present the ongoing efforts at the Paul Scherrer Institute in Switzerland where the n2EDM spectrometer has taken the first “physics data” in 2025. A large fraction of this dataset is dedicated to measurements of the UCN spectrum. I will present the newest UCN spectroscopy techniques that were recently published and the reasons for the importance of a deep understanding of the UCN spectrum.
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Hanno Filter (College 3 Secretary)
External visitors may ask for a site access to tellier(at)ill.fr
Zoom link : https://ill.zoom.us/j/98964195699?pwd=[REDACTED] – Password : [REDACTED]

Martial MARBOUTY (Institut Pasteur – Paris)
2026-03-26 13:00 - 14:00 | IMAG – Salle de Réunion, 150 place du Torrent, St Martin d’Hères, 38400, France
Phages with a broad host range are common across ecosystems
Contact : lucie.lamothe@univ-grenoble-alpes.fr

Jacopo DE NARDIS (Cergy Paris University)
2026-03-27 11:00 - 12:00 | LPMMC – salle Roger Maynard (G421), CNRS - LPMMC 25 avenue des Martyrs, Grenoble, 38042, France
Anticoncentration of Wave Functions and Information-Protected Phases in Noisy Quantum Chaotic Systems
Résumé :
I will present recent results on noisy quantum chaotic dynamics, with a particular focus on wave-function anticoncentration—characterized, for instance, through bitstrings output distributions—and on Information-protected phases that persist at finite circuit depth.
Contact : serge.florens@neel.cnrs.fr

Soutenance de Thèse de Mohammad CHORFA (IBS/Groupe Synchrotron)
2026-03-30 09:00 - 11:00 | IBS – Salle des séminaires, IBS 71 avenue des Martyrs, Grenoble, 38042, France
Effets de la dynamique structurale d’une famille de protéines fluorescentes infrarouges sur leurs propriétés de fluorescence
Résumé :
Ce travail de thèse consiste en une étude structurale approfondie d’une famille de protéines fluorescentes infrarouges (IFP) développées à partir du bactérophytochrome d’une bactérie Gram-négative du genre Bradyrhizobium, constituée de la protéine mIFP et de ses variants décalés vers le bleu iBlueberry et iBlueberry2. Les IFP présentent un fort intérêt en imagerie de corps entier en raison de l’existence d’une fenêtre optique des tissus entre 650 et 900 nm, au-dessus du domaine de longueur d’onde dans lequel l’hémoglobine et la déoxi-hémoglobine absorbent, et en-dessous du domaine dans lequel l’eau et les lipides absorbent et diffusent la lumière. Les protéines étudiées ici présentent un pic d’émission de fluorescence entre 660 et 720 nm.
Le bactériophytochrome et les IFP qui en sont dérivées utilisent la biliverdine, un produit du catabolisme des hèmes, comme chromophore afin d’absorber la lumière entre 640 et 690 nm. L’étude structurale a permis de montrer qu’une boucle localisée au voisinage de la biliverdine pouvait aborder un grand nombre de conformations, à la différence des autres phytochromes et IFP étudiés jusqu’à présent, où cette boucle ne semble posséder qu’une seule conformation. La conséquence de cette fluctuation conformationnelle est la présence d’une configuration du chromophore jamais encore observée menant à une conformation compacte du macrocycle formé par les quatre cycles pyrroles de la biliverdine, distincte de la conformation linéaire, ou étendue, habituellement observée. Les spectroscopies d’absorption UV-Visible et d’émissions de fluorescence in crystallo, c’est-à-dire directement appliquées aux cristaux, ont permis de montrer que la conformation compacte du chromophore menait à un pic d’émission de fluorescence au-delà de 760 nm pour iBlueberry et iBlueberry 2, et de 800 nm pour mIFP. Cette conformation semble être favorisé par l’empilement cristallin, et être seulement très faiblement peuplée en solution.
L’analyse des séquences de bactériophytochromes et d’IFP a permis de mettre en évidence la conformation particulière du coude beta au début de la boucle en question. L’ingénierie de ce coude beta chez un membre d’une autre famille de protéines fluorescentes a montré qu’elle permettait effectivement d’augmenter la plasticité de la boucle.
Ce travail donne des pistes pour modifier la configuration du chromophore au sein de la protéine par ingénierie rationnelle, notamment en utilisant des méthodes basées sur l’intelligence artificielle, et ainsi permettre d’obtenir de nouvelles IFPs avec des maxima d’émission en plein milieu de la fenêtre optique des tissus, afin de mieux utiliser celle-ci dans des expériences de marquage à plusieurs couleurs en imagerie tissulaire ou de corps entier.
Contact :ibs.seminaires@ibs.fr

Sander VAN SMAALEN (Laboratory of Crystallography, Bayerisches Geoinstitut, University of Bayreuth)
2026-03-30 14:00 - 15:00 | CNRS – Salle Louis Weil (E424), CNRS - Institut Néel 25 avenue des Martyrs, Grenoble, 38042, France
Chiral charge density waves in EuAl4 and related compounds
Résumé :
The BaAl 4 structure type has centrosymmetric, tetragonal symmetry, I4/mmm, with three crystallographically independent atom sites: Ba, Al1 and Al2. Solid solution series RAl 4-x Gax (R= Eu, Sr, Ca, Ba; 0 < x < 4) crystallize in this structure type [1], where Ga preferably occupies the Al2 site. Accordingly, complete chemical order is found for x = 0, 2, 4. Incommensurate charge-density waves (CDWs) have been observed in several of these ordered compounds. For the other values of x, lack of chemical order leads to suppression of the CDW transition. At much lower temperatures (T = 10–30 K) magnetic order appears for the compounds with magnetic Eu atoms. Here, we present the crystal structures of the incommensurate CDWs of EuAl 4 , EuAl 2 Ga2 and SrAl 4 . In particular, the symmetry of the CDWs is analyzed in view of x-ray diffraction data (present data [2–5]), and results of transmission electron microscopy (TEM), density functional theory (DFT) calculations and inelastic x ray scattering (IXS) from the literature [6–8].
References :
[1] M. Stavinoha et al., Phys. Rev. B 97, 195146 (2018). Charge density wave behavior and order-disorder in the antiferromagnetic metallic series Eu(Ga1-x Al x )4 .
[2] S. Ramakrishnan et al., IUCrJ 9, 378–385 (2022). Orthorhombic charge density wave on the tetragonal lattice of EuAl 4 .
[3] S. R. Kotla et al., Phys. Rev. B 112, 064113 (2025). Broken inversion symmetry in the charge density wave phase in EuAl 4 .
[4] S. Ramakrishnan et al., Phys. Rev. Research 6, 023277 (2024). Non-centrosymmetric, transverse structural modulation in SrAl 4 , and elucidation of its origin in the BaAl 4 family of
compounds.
[5] H. Agarwal et al., Phys. Rev. B 111, 155144 (2025). I-centered versus F-centered orthorhombic symmetry and negative thermal expansion of the charge density wave of EuAl2 Ga2 .
[6] H. Ni et al., Phys. Rev. Mater. 8, 104414 (2024). Real-space visualization of atomic displacements in a long-wavelength charge density wave using cryogenic 4D-STEM.
[7] A. N. Korshunov et al., Phys. Rev. B 110, 045102 (2024). Phonon softening and atomic modulations in EuAl 4 .
[8] F. Z. Yang et al., Nature Commun. 16, 10401 (2025). Incommensurate Transverse Peierls Transition and Signature of Chiral Charge Density Wave in EuAl4
Contact : andrew.fefferman@neel.cnrs.fr

Simon PONTON (chargé de recherche CNRS - SIMaP)
2026-03-31 14:00 - 15:00 | LMGP – salle des séminaires, Grenoble INP -Phelma 3 parvis Louis Néel, Grenoble, 38054, France
Development of the combinatorial approach for the CVD thin film deposition process : Multiphysics coupling and machine learning
Résumé :
The combinatorial approach applied to chemical vapor deposition processes integrating high-throughput experiments, computational simulations, and machine learning seems to emerge as a transformative paradigm to accelerate the discovery of novel materials. Through systematic gradient explorations, large-scale datasets can be generated to deepen our understanding of process-structure-property relationships. Machine learning models, trained on experimental and simulated data enable rapid prediction and identification of high-potential solutions, thereby guiding future experiments and simulations. The synergy not only reduces the time or cost associated with material discovery but also unlocks access to previously unexplored regions of the materials space.
Short Bio/CVMy academic journey began in Grenoble, where I studied chemistry before developing a keen interest in materials sciences, particularly nanostructures and their processing. Driven by a desire to unravel the underlying mechanisms, I started my PhD in Toulouse, between the CIRIMAT and LGC. There, I expanded my expertise in chemical engineering and Multiphysics simulation. After nearly two years of postdoctoral research, I sought to broaden my research perspective and joined Polytechnique Montréal in the chemical engineering section for two postdoctoral positions that led to an associate professor role. However, my longing for French cheese proved irresistible, I successfully secured a position at CNRS and joined SIMaP in February 2026.
Contact : deborah.verger@grenoble-inp.fr

Soutenance de Thèse de Espérance AHO (IBS/Groupe Structure et Activité des Glycosaminoglycanes)
2026-03-31 14:00 - 16:00 | IBS – Salle des séminaires, IBS 71 avenue des Martyrs, Grenoble, 38042, France
Structural and Functional effect of CXCL12/Heparan Sulfate Interactions at the Cell Surface
Résumé :
The glycocalyx is a protective layer covering the surface of cells, particularly endothelial cells, and represents a major regulator of cell-environment interactions. It functions as a mechanical barrier, a mechanosensor, and a signalling platform that controls vascular permeability. In inflammatory and tumor contexts, alterations in glycocalyx structure and density promote increased cell adhesion, extravasation, and metastatic dissemination. Structurally, the glycocalyx is composed of glycolipids, glycoproteins and proteoglycans bearing glycosaminoglycan (GAG) chains, including heparan sulfate (HS). These linear polysaccharides, organized into sulfated and non-sulfated domains, interact with numerous proteins, including growth factors and chemokines, thereby modulating their bioavailability and biological activity. Notably, chemokine-HS interactions are essential for the formation of chemotactic gradients involved in leukocyte recruitment, inflammatory extravasation, and tumor progression. The chemokine CXCL12 (stromal cell-derived factor-1, SDF-1), a member of the CXC chemokine family, exists as six distinct isoforms generated by alternative splicing of the CXCL12 gene. These isoforms share a common N-terminal sequence but differ in their C-terminal extensions, which influence their interactions with HS. Among them, CXCL12γ isoform, characterized by its exceptionally high affinity for HS, represent a particularly relevant candidate.
This work builds upon previous findings from our group showing, using biophysical approaches (QCM-D, FRAP), that CXCL12 is able to induce cross-linking of HS chains on biomimetic surfaces, resulting in HS rigidification, decreased layer thickness, and reduced HS lateral mobility. These observations suggest that chemokine-HS interactions can modify the physical properties of HS beyond a simple ligand-presentation role. The central hypothesis of this project is that binding of the CXCL12γ to HS induces remodelling of the endothelial glycocalyx at the cell surface thereby changing cellular mechanical properties and promoting immune cell adhesion. Here, we investigate the impact of CXCL12γ on HS organization across molecular, nanoscale, and cellular levels by combining biomimetic surfaces, biophysical approaches, super-resolution microscopy, and cell-based assays.
We show that CXCL12γ reorganizes HS chains at the endothelial cell surface and that all HS-binding sites are required for efficient HS rigidification and network reorganization. CXCL12γ-driven remodeling of the glycocalyx reduces HS thickness and alters its nanoscale topology, thereby promoting paracellular permeability and formation of adhesive platforms that facilitate leukocyte capture, and firm adhesion.
Contact : ibs.seminaires@ibs

Soutenance de Thèse de Simon VERNIER
2026-04-01 14:00 - 16:00 | Phelma minatec, Salle Z108, Grenoble INP - Phelma, 3 parvis Louis Néel, Grenoble, 38000, France
Optimisation et caractérisation avancée de couches minces de zircone stabilisée à l’yttrine par dépôt chimique d’organométalliques en phase vapeur pour des cellules électrochimiques à oxydes solides
Résumé :
Notre consommation énergétique et l’électrification de notre production afin de la décarboner. Le développement des énergies solaire et éolienne est cependant freiné par leur défaut principal : leur intermittence. Le stockage saisonnier de l’énergie sous forme d’hydrogène est une solution prometteuse pour pallier à ce défaut. EPISTORE est un projet de recherche européen visant au développement d’une cellule électrochimique à oxydes solides (SOC), réversible, en couche mince, basse température (< 500°C). Ces dispositifs sont en effet particulièrement pertinents pour la conversion électricité-gaz.
Cette thèse, dans le cadre d’EPISTORE, projet du programme de recherche et d’innovation Horizon 2020, vise au développement de couches minces de zircone stabilisée à l’yttrine (YSZ) pour servir d’électrolyte pour ces SOCs. Le YSZ, contenant 8 mol% d’yttrine (8YSZ) est un matériau déjà largement utilisé comme électrolyte dans les dispositifs électrochimiques en céramique. Ses propriétés lui permettent de conduire efficacement les ions oxygènes tout en formant une barrière électronique. L’étude des couches minces de YSZ fabriquées au cours de cette thèse doit permettre d’évaluer la pertinence de réduire la quantité d’yttrine dans le matériau. En effet, les travaux publiés sur le sujet suggèrent qu’une concentration de 3 mol% ou 4 mol% d’yttrine pourraient améliorer les propriétés mécaniques, vitales pour des dispositifs en couches minces.
Ce travail détaille l’optimisation de la synthèse de ces films par dépôt chimique en phase vapeurs d’organométalliques (MOCVD) puis la caractérisation avancée de ces échantillons, non seulement structurellement et morphologiquement (XRD, TEM, SEM, Raman…) mais aussi de leurs propriétés électriques via de la spectroscopie d’impédance électrochimique (EIS) ou mécaniques via nanoindentation et tests de déformation. Une nouvelle technique d’observation directe de la diffusion ionique impliquant des traceurs isotopiques et de la spectroscopie Raman a aussi été adaptée à ce matériau pour la première fois.
Les résultats obtenus suggèrent que l’emploi de 3YSZ et 4YSZ à basse température (< 500 °C) permettent d’obtenir des performances électrochimiques équivalentes ou supérieures au 8YSZ. Un effet positif de ce changement de concentration sur les propriétés mécaniques des films n’a cependant pas été démontré.
Contact : deborah.verger@grenoble-inp.fr
