Youngsuk KIM (Pusan National University, Busan, South Korea (visiting scientist @ DCM))
2026-02-12 14:00 - 15:00 (Europe/Paris) | DCM – Salle C209, DCM - Bât Chimie Recherche 301 rue de la Chimie, St Martin d'Hères, 38400, France
Carbene–CS2 : Redox-active Radical Ligands
Contact : david.martin@univ-grenoble-alpes.fr

Roxane LESTINI & Nicolas OLIVIER (Laboratoire d'Optique et Biosciences, Palaiseau)
2026-02-16 11:00 - 12:00 | LiPhy, Salle de Conférence, 140 rue de la Physique, St Martin d'Hères, 38400
Understanding DNA replication dynamics in the archaea Haloferax volcanii
Résumé :
Archaea provide a simplified yet highly informative model for deciphering the complex regulatory networks governing DNA replication and origin firing. Among them, Haloferax volcanii has a circular chromosome with four active replication origins distributed across a 3.5 Mb DNA molecule and exhibit some distinctive properties, such as a heterogeneous polyploidy, carrying 10–18 copies of its genome.
How these highly polyploid organisms regulate the activation and timing of their multiple replication origins in coordination with cell growth and division remains an open question. To address this question, we developed a multiscale approach, implementing the STORM technique in archaea for the first time, Marker Frequency Analysis by sequencing (MFA-seq) to capture the global replication profile at the population level, and fluorescence in situ hybridization (FISH) to explore ploidy variation.
Our findings reveal, with an unprecedented resolution of ~30 nm, new insights into the spatial regulation of replication foci, demonstrating their organization into clusters. We further investigated DNA replication dynamics under varying growth conditions, revealing a reduction in replication foci number that correlates with decreased replication rates and DNA content. By contrast, altering the replication initiation mode—by inactivating all four replication origins—does not disrupt the overall replication dynamics.
By integrating these techniques, we aim to characterize the replication program in H. volcanii and gain a deeper understanding of its regulation.
Contact : delphine.debarre@univ-grenoble-alpes.fr

Igor ROZHANSKIY (National Graphene Institute, University of Manchester)
2026-02-17 14:00 - 15:00 | CEA – Salle de Séminaire IRIG (1005 – 445), Laboratoire Irig/Spintec, salle de séminaire 445, bâtiment 1005, CEA-Grenoble, Grenoble
Interacting spin physics in 2D : flat bands, SOC renormalization, and chiral textures
Résumé :
Two-dimensional materials and their heterostructures offer a controllable setting where exchange, spin-orbit coupling (SOC), and electron interactions shape the spin-resolved electronic structure and response. This seminar links two recent directions of my work through this common theme.
The first part focuses on van der Waals magnets (chromium trihalides) combined with graphene. Narrow, spin-polarized conduction bands make these systems susceptible to charge-transfer-driven doping and strong correlations. Using DFT-calibrated effective tight-binding models, I will show how flat-band features and longer-range hopping processes determine the low-energy spectrum and favor regimes with heavy, strongly interacting carriers.
​ The second part addresses many-body renormalization of SOC in monolayer transition metal dichalcogenides. Exchange effects can enhance the conduction-band spin-orbit splitting in a density-dependent manner. I will outline ​the underlying mechanism and discuss how it can be inferred from gated transport and quantum-oscillation measurements, including multilayer configurations where valley structure and interlayer coupling provide additional diagnostics.
A short outlook will touch on chiral spin textures, such as skyrmions, and how real-space chirality can contribute to transverse signals, emphasizing possible connections and open questions for 2D material platforms.
https://www.cea.fr/drf/irig/Pages/Animation-scientifique/seminaires/2026_Rozhanskiy.aspx
Contact : admin.spintec@cea.fr

Anton POTOCNIK (IMEC, Belgium)
2026-02-17 14:00 - 15:00 | CNRS – Salle Rémy Lemaire (K223), CNRS - Institut Néel 25 avenue des Martyrs, Grenoble, 38042, France
High-coherence foundry-compatible superconducting qubit platform
Résumé :
The field of superconducting qubit technology has experienced rapid development over the past two decades. Recent advancements in the fabrication, control and measurement of superconducting quantum devices have enabled integration of hundreds of qubits on a single chip. However, the path towards larger-scale integration of thousands of qubits on a chip remains unclear. This talk presents imec’s platform for scalable superconducting qubit fabrication, which is based on foundry-compatible thin film processing 1 and overlay Josephson-junction fabrication 2. The platform enables all-optical superconducting transmon qubit fabrication on 300 mm wafers, achieving near state-of-the-art coherence times, record-low aging and comparable Josephson junction variability to standard shadow-evaporation technique 3. A key focus of this presentation will be the understanding and mitigation of microwave losses induced by various fabricaiton steps such as Ar-milling 4 and oxide removal 6,7 and materials such as -Ta 5 or ultra-high-resistivity silicon. The talk will conclude with an outline of ongoing efforts toward large-scale qubit characterization and control using cryo-CMOS electronics operating near qubits at the mixing-chamber plate of a dilution refrigerator 8.
1 Mongillo, et al., IEDM (2022).
2 Verjauw et al., npj Quantum Information 8, 93 (2022).
3 Van Damme, et al., Nature, 634, 74 (2024).
4 Van Damme, et al., PRA 20, 014034 (2023).
5 Lozano, et al. Mater. Quantum. Technol. 4, 025801 (2024).
6 Verjauw, et al., PRA 16, 014018 (2021).
7 Lozano, et al., Advanced Science 12, e09244 (2025).
8 Acharya, et al., Nature Electronics, 6, 900 (2023).
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Contact : equipe-seminaires-nano@listes.grenoble.cnrs.fr

Francesco ROSA (Politecnico di Milano, Italy)
2026-02-17 14:00 - 15:00 | CNRS – Salle Louis Weil (E424), CNRS - Institut Néel 25 avenue des Martyrs, Grenoble, 38042, France
Magnetic and orbital properties of infinite-layer nickelate and cuprate superconductors
Résumé :
Infinite-layer (IL) nickelates recently gained strong interest thanks to their apparent analogies with cuprates, including a square lattice-based structure dominated by superexchange antiferromagnetic interaction and the emergence of superconductivity upon hole doping. X-ray spectroscopies with synchrotron light are a very powerful tool for the investigation of such systems, providing complementary information to the more traditional inelastic neutron scattering. In this seminar, we discuss some of the recent results obtained by our group using both Resonant Inelastic X-ray Scattering (RIXS) and X-ray Magnetic Circular Dichroism (XMCD), mainly focusing on magnetism. RIXS results concern the analysis of dynamic spin excitations (magnons/paramagnons), investigating the effect of hole-doping on them and providing an estimate for the magnetic exchange coupling constants. Results on IL nickelates will be compared to analogous ones on cuprates, highlighting analogies and differences. XMCD analysis is devoted to the static spin order in IL nickelates, reporting the presence of a field induced out-of-plane Ni1+ spin moment. Based on magnetic field- and temperature-dependent measurements, we justify our observations with an out-of-plane canting of in-plane anti-ferromagnetically correlated Ni1+ spins, tentatively attributed to a symmetry lowering of the NiO2 planes.
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Contact : andrew.fefferman@neel.cnrs.fr

Sharlen MOORE (Johns Hopkins University, Baltimore, USA)
2026-02-19 11:30 - 12:30 | GIN – Amphi Serge Kampf, Grenoble Institut des Neurosciences (GIN) Bât. Edmond J. Safra, Chemin Fortune Ferrini CHU, La Tronche, 38700, France
Revealing abrupt transitions from goal-directed to habitual behavior
Résumé :
A fundamental tenet of animal behavior is that decision-making involves multiple ‘controllers.’ Initially, behavior is goal-directed, driven by desired outcomes, shifting later to habitual control, where cues trigger actions independent of the motivational state. Clark Hull’s question from 1943 still resonates today: “Is this transition [to habit] abrupt, or is it gradual and progressive?” Despite a century-long belief in gradual transitions, this question remains unanswered as current methods cannot disambiguate goal-directed versus habitual control in real time. Here, we introduce a novel ‘volitional engagement’ approach, motivating animals by palatability rather than biological need. Providing less palatable water in the home cage reduced motivation to ‘work’ for plain water in an auditory discrimination task compared to water-restricted animals. Using quantitative behavior and computational modeling, we found that palatability-driven animals learned to discriminate as quickly as water-restricted animals but exhibited state-like fluctuations when responding to the reward-predicting cue-reflecting goal-directed behavior. After thousands of trials, these fluctuations spontaneously and abruptly ceased, with animals always responding to the reward-predicting cue. In line with habitual control, post- transition behavior displayed motor automaticity, decreased error sensitivity (assessed via pupillary responses), and insensitivity to sensory-specific outcome devaluation. Bilateral lesions of the habit-related dorsolateral striatum (DLS) blocked transitions to habitual behavior. Finally, we used bilateral fiber photometry in the putative controllers of goal-directed (dorsomedial striatum, DMS) and habitual (DLS) behavior to monitor the evolution of neural activity across learning. Both the DMS and DLS exhibited learning- related signatures in cue, lick, and outcome-related signaling at similar timescales in parallel. Immediately after transitioning to habitual behavior, outcome-related signaling was suppressed in the DLS and, to a lesser extent, in the DMS, while cue-evoked responses further sharpened. This abrupt shift (reduction in outcome signaling and sharpening of cue-evoked responses) suggests that sensory cues rather than outcomes drive habitual responding. Our results demonstrate that both controllers (DMS and DLS) exhibit learning-related plasticity in parallel but that the behavioral manifestation of habits emerges spontaneously and abruptly in a DLS-dependent manner, suggesting the involvement of a higher-level process that arbitrates between the two.
Contact : robin.magnard@univ-grenoble-alpes.fr

Dmitri KHVESHCHENKO (University of North Carolina)
2026-02-20 11:00 - 12:00 | LPMMC, CNRS - Bat G, salle Roger Maynard G-421, Grenoble
Applied Hall-o-graphy with no strings attached
Résumé :
This discussion aims at ascertaining the true status of the so-called applied-holographic approach to strongly correlated quantum matter. The latter ranges from ‘not even wrong’ for the constructions based on the ad hoc ‘AdS/CMT’ to ‘might be right, albeit for the wrong reason’ for those emerging in the context of phase-space bosonization and the related ‘Hall-o-graphic’ hydrodynamics.The presentation will be made accessible to the wide audience of non-experts and students.
Contact : serge.florens@neel.cnrs.fr

Mourad CHABBI (docteur en sciences politiques, GEM / « Géopolitique ») & Ludivine CALAMEL (professeur Senior en sciences de gestion, GEM)
2026-02-20 12:30 - 13:15 | Amphi Minatec, 3 parvis Louis Néel, Grenoble, 38054, France
L’impact du contexte géopolitique sur l’évolution des règles et du marché des semi-conducteurs
Résumé :
Cette conférence s’intéresse à la manière dont le contexte géopolitique impacte les organisations, et notamment certaines gravitant dans le domaine de la micro-électronique (semi-conducteurs).
Contact : giant.campus@cea.fr

Sophie Abby (TIMC, Grenoble)
2026-02-24 18:30 | Museum de Grenoble, 1 Rue Dolomieu, Grenoble, 38000, France
Le premier souffle : comment les microbes ont oxygéné la Terre
Résumé :
Cette soirée explore la diversité du vivant à travers l’arbre phylogénétique, en s’appuyant sur les travaux du projet Quinevol qui étudie les quinones, molécules essentielles présentes dans tous les organismes vivants. Comment les organismes primitifs respiraient-ils avant l’apparition de l’oxygène ? Comment se sont-ils ensuite adaptés à ce qui était alors un véritable poison ? Un voyage scientifique des origines de la vie jusqu’aux frontières de la recherche actuelle.

Céline SCORNAVACCA (ISEM – Montpellier)
2026-02-26 13:00 - 14:00 | IMAG – Salle de Réunion, 150 place du Torrent, St Martin d’Hères, 38400, France
A New Algorithm for Computing the Likelihood of a Phylogeny
Contact : lucie.lamothe@univ-grenoble-alpes.fr

Paulo Henrique MACIEL BUZZETTI (Département de Chimie Moléculaire, équipe I2BM (nouvel entrant))
2026-02-26 14:00 - 15:00 | DCM – Salle C209, DCM - Bât Chimie Recherche 301 rue de la Chimie, St Martin d'Hères, 38400, France
From Bio-analytics & Bio-energy : A Journey Through Functional Interfaces & Supramolecular Architectures
Contact : quentin.laurent@univ-grenoble-alpes.fr

Rolf LORTZ (CNRS-LNCMI, Grenoble)
2026-02-26 14:00 - 15:00 | CNRS – Salle Rémy Lemaire (K223), CNRS - Institut Néel 25 avenue des Martyrs, Grenoble, 38042, France
High temperatures superconductivity with giant pressure effect in 3D networks of boron doped ultra-thin carbon nanotubes in the pores of ZSM-5 zeolite
Résumé :
We report the fabrication of three‑dimensional, interconnected networks of ultrathin carbon nanotubes (CNTs) embedded within the ~5 Å pores of zeolite ZSM‑5 crystals using a controlled chemical vapour deposition (CVD) process. Confinement within these sub‑nanometre channels yields CNTs with strongly one‑dimensional electronic characteristics, including pronounced van Hove singularities in the density of states. By introducing boron dopants during growth, we strategically tune the Fermi level toward a van Hove singularity, as supported by ab initio electronic‑structure calculations. This electronic tuning, combined with the intrinsic 3D connectivity of the CNT–zeolite framework, enables a dimensional crossover from 1D electronic states to a phase‑coherent, bulk superconducting state.
To establish the presence of superconductivity, we employ five complementary experimental probes—electrical resistivity, ac susceptibility, dc magnetization, specific heat, and point‑contact spectroscopy. All measurements consistently indicate a superconducting transition at ambient pressure with a critical temperature Tc in the range of 220–250 K. Simultaneous resistivity and ac‑susceptibility measurements reveal a three‑order‑of‑magnitude drop in resistance accompanied by the onset of a robust Meissner effect with nearly perfect diamagnetic screening. Point‑contact spectroscopy further uncovers a multigap superconducting state, with a dominant gap of approximately 30 meV, in reasonable agreement with expectations from Bardeen–Cooper–Schrieffer (BCS) theory. The differential conductance spectra exhibit clear particle–hole symmetry and evolve smoothly between the tunnelling and Andreev reflection regimes as the contact transparency is varied—behaviour uniquely characteristic of superconducting quasiparticles. Specific‑heat measurements show a distinct anomaly at the transition, reminiscent of signatures observed in high‑Tc cuprate superconductors.
Finally, we find that the application of very modest external pressure further enhances the superconducting transition temperature, pushing Tc above ambient temperature and suggesting that the system remains far from its optimal tuning point. These results collectively point to a new pathway for achieving high‑temperature superconductivity in engineered low‑dimensional carbon‑based materials.
Contact : florence.levy-bertrand@neel.cnrs.fr

Jean-Francois COLLET (Institut de Duve, Bruxelles)
2026-02-27 11:00 - 12:00 | IBS – Salle des séminaires, IBS 71 avenue des Martyrs, Grenoble, 38042, France
How (and Why) do Gram-Negative Bacteria build an Outer Membrane
Résumé :
Gram-negative bacteria are defined by a complex cell envelope in which the outer membrane plays a central role in protection, nutrient exchange, and antibiotic resistance. This asymmetric lipid bilayer forms a robust permeability barrier, yet its biogenesis presents a striking challenge : all outer membrane components are synthesized in the cytoplasm or at the inner membrane and must be transported and assembled across the periplasm without direct energy input. In this talk, I will discuss how Gram-negative bacteria build their outer membrane and why this process is essential for cellular physiology. I will introduce the major pathways responsible for outer membrane assembly and highlight how their activities need to be coordinated to maintain envelope integrity. I will also present recent work showing that the outer membrane is not merely a passive barrier, but a mechanically active structure that enables the buildup of periplasmic pressure, a property critical for envelope stability and bacterial survival. Together, these findings underscore the outer membrane as a dynamic, multifunctional organelle and a promising target for future antibacterial strategies.
Contact : ibs.seminaires@ibs.fr

Moritz SENGER (Université d’Uppsala, Département de chimie pour les sciences de la vie, Suède)
2026-03-02 11:00 - 12:00 | IBS – Salle des séminaires, IBS 71 avenue des Martyrs, Grenoble, 38042, France
From Catalysis to Sensing : Proton Transfer in [FeFe]-hydrogenases
Résumé :
Enzymes are natures catalysts enabling challenging reactions at ambient conditions and at low overpotentials. In particular, [FeFe]-hydrogenases which catalyse bidirectional H2 turnover (2e- + 2H+ <-> H2) at high turnover numbers raise interest for their application in a green hydrogen economy. In [FeFe]-hydrogenases catalysis takes place at a unique diiron cofactor that is equipped with carbon monoxide (CO) and cyanide (CN) ligands. They serve as intrinsic infrared active probes sensitive to redox changes located directly at the centre of the catalytic reaction. This in isolation inactive di-iron cofactor becomes efficient H2 catalyst when incorporated into the [FeFe]-hydrogenase protein scaffold. More recently H2 sensing [FeFe]-hydrogenases have been characterised using the identical cofactor but for H2 sensing. The fundamental design principles of the protein scaffolds to selectively tune cofactor function either to efficient H2 catalyst or to H2 sensor remain unknown.Here we use organic dyes to artificially activate catalytic [1-2] and sensory [3-5] [FeFe]-hydrogenases photochemically and investigate them via in situ ATR-FTIR spectroscopy. Following changes of the cofactor CO and CN ligands, single carboxylic acid residues and collective amide I modes, we show that protein scaffold differences are not limited to the cofactor second coordination sphere but extend through the whole protein via proton transfer pathways, secondary structure changes and most likely dimerization events. More general, our results give a first idea how protein scaffolds can tune cofactor functions.
References :[1] M. Senger, V. Eichmann, K. Laun, J. Duan, F. Wittkamp, G. Knor, U. P. Apfel, T. Happe, M. Winkler, J. Heberle and S. T. Stripp*J Am Chem Soc, 2019, 141, 17394-17403.[2] M. Lorenzi, M. T. Gamache, H. J. Redman, H. Land, M. Senger* and G. Berggren*ACS Sustain Chem Eng, 2022, 10, 10760-10767.[3] I. Voloshyn, C. Schumann, P. R. Cabotaje, A. Zamader, H. Land and M. Senger*Chem Commun (Camb), 2024, 60, 10914-10917[4] M. Senger*, C. Schumann, P. R. Cabotaje, A. Zamader, P. Huang, H. Land and G. Berggren*Phys Chem Chem Phys, 2025, 27 (18), 9864-9875 [5] Cabotaje, P. R. ; Sekretareva, A. ; Senger, M. ; Huang, P. ; Walter, K. ; Redman, H. J. ; Croy, N. ; Stripp, S. T. ; Land, H. ; Berggren, G.J Am Chem Soc 2025, 147 (5), 4654-4666.
Contact : ibs.seminaires@ibs.fr

Matteo MILANI (ESPCI Paris)
2026-03-02 11:00 - 12:00 | LiPhy, Salle de Conférence, 140 rue de la Physique, St Martin d'Hères, 38400
Rheofluidics: single-drop oscillatory rheology with microfluidics
Résumé :
The measurement of frequency-dependent viscoelastic moduli is of paramount importance in many fields, from material science to biology, and is typically accomplished in bulk materials using commercial rheometers. The trend towards miniaturization in the biotechnology, manufacturing and chemical processing industries has motivated the extension of viscoelastic measurements to microscopic objects with well-defined shape and size such as droplets, vesicles, microcapsules, or even single cells. For instance, local mechanical probes such as AFM nanoindentation can be used to probe single-cell stiffness, and micropipette aspiration probes the interfacial properties of droplets and vesicles. Despite their versatility, these techniques are characterized by complex deformation geometries and a relatively low throughput, which makes them unfit to sample highly heterogeneous populations such as those typical of biological samples. To this end, novel microfluidic approaches have been recently developed to measure the stiffness of cells and droplets flowing through narrow channels. These approaches are well-suited for applications requiring a high throughput, but they lack the fine control of stress and strain required by quantitative mechanical measurements. Here, we present a novel technique called Rheofluidics, which combines the high throughput of microfluidics with the versatility of traditional rheological probes. Like a stress-controlled rheometer, Rheofluidics measures the time-dependent deformation of droplets subject to a well-defined hydrodynamic stress, whose time evolution is controlled by the shape of the microfluidic channel in which the droplets are flowing. To validate this approach and to demonstrate the power of this technique, we study the linear and nonlinear rheology of oil droplets, hydrogel beads and lipid vesicles, extracting their viscoelastic properties with a throughput more than 1000 times higher than that of standard rheology.
Contact : gwennou.coupier@univ-grenoble-alpes.fr

Ran TAO (Institut Néel)
2026-03-02 14:00 - 15:00 | CNRS – Salle Louis Weil (E424), CNRS - Institut Néel 25 avenue des Martyrs, Grenoble, 38042, France
Magnetic excitations in LuFe2Ge2
Résumé :
The iron-based superconductor YFe2Ge2 (Tc ~ 1.8 K)[1] has attracted interest due to strong electronic correlations[2] and shows enhanced magnetic fluctuations in neutron scattering[3]. Its isoelectronic and isostructural sister compound LuFe2Ge2 orders antiferromagnetically below TN ~ 6.8 K, and in clean crystals shows a resistive superconducting transition below 1 K. We present recent inelastic neutron scattering experiments on LuFe2Ge2 in the ordered and paramagnetic phases. The excitations are modelled with linear spin wave theory, and we note some similarities to previous results in paramagnetic YFe2Ge2.
[1] J. Chen et al., Phys. Rev. Lett. 125, 237002 (2020).
[2] J. Baglo et al. Phys. Rev. Lett. 129, 046402 (2022). B. Xu et al., Proc. Natl. Acad. Sci. U. S. A. 121, e2401430121 (2024).
[3] H. Wo et al., Phys. Rev. Lett. 122, 217003 (2019).
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Contact : andrew.fefferman@neel.cnrs.fr

Marco MACCARINI (chercheur UGA)
2026-03-03 14:00 | LMGP – salle des séminaires, Grenoble INP -Phelma 3 parvis Louis Néel, Grenoble, 38054, France
Exploring the Nanostructure of Biomimetic Membranes
Résumé :
Model lipid membranes are simplified yet powerful systems that mimic key features of biological plasma membranes—the essential envelopes that define and protect living cells. Their controlled simplicity makes them ideal for precise experimental techniques, enabling us to explore their interactions with novel nanoengineered materials.
When combined with biological components like proteins, these membranes not only deepen our understanding of fundamental biological processes but also serve as building blocks for advanced nanoengineered materials with tailored technological applications.
In this seminar, I will present examples from my research, where laboratory techniques, large-scale facility analyses, and computational methods converge to provide in-depth characterization and mechanistic insights into membrane behavior. These findings hold significant potential for advancements in health, biotechnology, and fundamental biology.
Short Bio/CV
As a CNRS Chargé de Recherche, I’ve recently joined the LMGP to continue my research journey in this scientific new environment. My academic path has taken me across borders—starting with a Physics degree in Italy, followed by a PhD in Polymer Physics in England, and postdoctoral experiences in Germany and Canada. Along the way, I’ve had the privilege of working at world-class facilities like the Institut Laue Langevin, where I deepened my expertise in large-scale scientific infrastructure. I now continue this work at LMGP, where my research focuses on the intersection of physics, materials science, and biomimetic systems.
Contact : deborah.verger@grenoble-inp.fr

Viviana RICON MONTES & Andreas OFFENHÄUSSER (Forschungszentrum Jülich, Allemagne)
2026-03-05 11:30 - 12:30 | GIN – Amphi Serge Kampf, Grenoble Institut des Neurosciences (GIN) Bât. Edmond J. Safra, Chemin Fortune Ferrini CHU, La Tronche, 38700, France
Devices that interact with the brain: from nanostructured to flexible electrodes
Résumé :
Neural electrodes are the core components of neuroelectronic devices, enabling the recording and simulation of neural activity. Our research focuses on two primary areas : (1) the design and
characterization of the neuron-electrode interface, and (2) the development of flexible neural interfaces for both in vivo and in vitro applications. Microelectrode arrays (MEAs) are commonly used to bridge the interface between neurons and electronic systems. However, current MEAs face limita7ons in signal fidelity, precision of neural modulation, and long-term biocompatibility. To address these challenges, we are developing nanomaterial-based MEAs that offer enhanced physical and chemical properties, leading to improved cell-electrode coupling. Specifically, we have engineered a hybrid structure combining vertical nanostraws with nanocavities, enabling stable, non-invasive, and long-term recording at sub-threshold resolution.
Implantable neural prosthetic devices provide direct access to local neural circuits and are critical components of brain-machine interfaces. While current clinical-grade devices—typically based on silicon or noble metals—have driven significant advances, they oPen fail to sustain reliable neural communication over extended periods. Our goal is to create next-generation neurotechnologies that integrate seamlessly with biological tissue, supporting multimodal neural interrogation through electrical, optical, or chemical means. We are actively exploring novel device architectures, materials, and implantation strategies, alongside rigorous performance evaluation, with the ultimate aim of enabling both acute and chronic in vivo applications. Our approach combines thin-film technology and surface micromachining processes with additive manufacturing techniques, including two-photon lithography. These are integrated with self-
aligned, template-assisted electrodeposition processes, kirigami-inspired designs with matched-die forming, novel bonding methods, and the modular stacking of two-dimensional neural probes with key-lock systems. These technologies support versatile applications, ranging from investigating seizure-like activity in in vitro epilepsy models to advancing visual prosthesis that enable bidirectional communication along the visual pathway.
Contact : clement.hebert@univ-grenoble-alpes.fr

Dalila BOUNOUA (LLB)
2026-03-05 14:00 - 15:00 | CNRS – Salle Rémy Lemaire (K223), CNRS - Institut Néel 25 avenue des Martyrs, Grenoble, 38042, France
Polarized Neutrons Reveal Altermagnetism in MnF2
Résumé :
Altermagnets constitute a recently identified class of collinear, magnetically compensated materials in which oppositely oriented magnetic sublattices cannot be mapped onto each other another by a primitive lattice translation or inversion operation. Unlike conventional antiferromagnets, altermagnets break time-reversal symmetry. These distinctive symmetry properties give rise to spin-split electronic bands and chirality-split magnon branches, both exhibiting characteristic anisotropic patterns in momentum space, even in the absence of relativistic spin-orbit coupling [1].
Experimental evidence for spin-split electronic bands has been reported in materials such as MnTe and CrSb using angle-resolved photoemission spectroscopy (ARPES) [2,3], while resonant inelastic X-ray scattering (RIXS) has revealed chiral magnon excitations in CrSb [4]. Polarized neutron scattering, however, provides a unique probe of altermagnetism, as it enables a direct characterization of spin-wave excitations and allows both split magnons [5-7] and their associated chirality [8-10] to be measured simultaneously.
In this work, we investigated the chirality-split magnon spectrum of MnF₂ [9] using polarized inelastic neutron scattering (INS). Our measurements reveal, for the first time in MnF₂, a small but clearly resolvable splitting of the magnon branches, primarily driven by long-range dipolar interactions. Polarization analysis on a magnetically domain-biased sample further uncovers a finite chiral contribution to the neutron scattering cross section, which reverses sign between the two split magnon modes. These observations provide direct spectroscopic evidence of altermagnetism in MnF₂.
[1] G. L. Smejkal et al., Phys. Rev. X 12, 040501 (2022).
[2] J. Krempasky, et al., Nature 626, 517–522 (2024).
[3] S. Reimers et al., Nat. Comm 15, 2116 (2024), G. Yang et al. Nat Commun 16, 1442 (2025).
[4] N. Biniskos et al., Nat Commun 16, 9311 (2025).
[5] Z. Liu Phys. Rev. Lett. 133, 156702 (2024).
[6] Q. Sun et al., Phys. Rev. Lett. 135, 18 (2025).
[7] A. K. Singh et al., arXiv:2511.16086.
[8] P. A. McClarty et al., Phys. Rev. B 111, L060405 (2025).
[9] Q. Faure at al., arXiv:2509.07087 (under review).
[10] J. Sears et al., arXiv:2601.04303v1

Contact : elsa.lhotel@neel.cnrs.fr

Kilian FRABOULET (Max Planck Institute Stuttgart)
2026-03-06 11:00 - 12:00 | 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

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

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

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

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

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)

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
