BEGIN:VCALENDAR VERSION:2.0 PRODID:-//FeRMI - ECPv6.15.20//NONSGML v1.0//EN CALSCALE:GREGORIAN METHOD:PUBLISH X-WR-CALNAME:FeRMI X-ORIGINAL-URL:https://fermi.univ-tlse3.fr X-WR-CALDESC:Évènements pour FeRMI REFRESH-INTERVAL;VALUE=DURATION:PT1H X-Robots-Tag:noindex X-PUBLISHED-TTL:PT1H BEGIN:VTIMEZONE TZID:Europe/Paris BEGIN:DAYLIGHT TZOFFSETFROM:+0100 TZOFFSETTO:+0200 TZNAME:CEST DTSTART:20230326T010000 END:DAYLIGHT BEGIN:STANDARD TZOFFSETFROM:+0200 TZOFFSETTO:+0100 TZNAME:CET DTSTART:20231029T010000 END:STANDARD BEGIN:DAYLIGHT TZOFFSETFROM:+0100 TZOFFSETTO:+0200 TZNAME:CEST DTSTART:20240331T010000 END:DAYLIGHT BEGIN:STANDARD TZOFFSETFROM:+0200 TZOFFSETTO:+0100 TZNAME:CET DTSTART:20241027T010000 END:STANDARD BEGIN:DAYLIGHT TZOFFSETFROM:+0100 TZOFFSETTO:+0200 TZNAME:CEST DTSTART:20250330T010000 END:DAYLIGHT BEGIN:STANDARD TZOFFSETFROM:+0200 TZOFFSETTO:+0100 TZNAME:CET DTSTART:20251026T010000 END:STANDARD END:VTIMEZONE BEGIN:VEVENT DTSTART;TZID=Europe/Paris:20241015T140000 DTEND;TZID=Europe/Paris:20241015T170000 DTSTAMP:20260413T223644 CREATED:20241007T074132Z LAST-MODIFIED:20241009T091623Z UID:11009-1729000800-1729011600@fermi.univ-tlse3.fr SUMMARY:Source d’atomes ultra-froids pour les capteurs quantiques embarqués : conception et mise en œuvre d’une puce magnétique à réseau. - (Romain Calviac / Thèse / LCAR-LAAS)\, 15/10/2024\, 14H DESCRIPTION:Soutenance de thèse \nRomain Calviac FeRMI\, Salle de conférence 3R4 \nComposition du jury: \n\nAlexandre Gauguet\, directeur de thèse\, LCAR\nOlivier Gauthier-Lafaye\, directeur de thèse\, LAAS\nBaptiste Allard\, co-encadrant\, LCAR\nAntoine Monmayrant\, co-encadrant\, LAAS\nAgnès Maître\, rapporteuse\, Sorbonne Université\nJacob Reichel\, rapporteur\, LKB\, Ecole Normale Supérieure \nBaptiste Battelier\, examinateur\, LP2N\, Bordeaux\nClément Lacroute\, examinateur\, FEMTO-ST\nPierre Renucci\, examinateur\, INSA Toulouse\nThomas Lévèque\, invité\, CNES\n\n  \nRésumé:\nMes travaux de thèse s’inscrivent dans le contexte du développement de capteurs quantiques à onde de matière embarqués. Ces instruments\, relativement complexes\, étaient jusqu’à récemment principalement utilisés en laboratoire. Aujourd’hui\, les techniques d’interférométrie atomique ont suffisamment évolué pour permettre leur utilisation en dehors de ces derniers. Cependant\, l’environnement embarqué ajoute un ensemble de contraintes supplémentaires. Ainsi\, les systèmes laser\, le système de contrôle\, la chambre à ultra-vide ainsi que la source d’atomes froids ou ultra-froids constituant ces capteurs doivent répondre à plusieurs exigences : être compacts\, robustes\, consommer peu d’énergie et être transportables. Ma thèse s’est donc concentrée sur la conception d’une nouvelle source d’atomes ultra-froids répondant à ces contraintes. Là où les dispositifs similaires utilisent au moins trois faisceaux laser\, la source que j’ai conçue est capable de! générer un condensat de Bose-Einstein avec un seul faisceau. Pour cela\, j’ai dimensionné un réseau de diffraction permettant de réaliser un piège magnéto-optique à un faisceau. Celui-ci a été assemblé avec une puce magnétique que j’ai également conçue. Par la suite\, j’ai mis en œuvre cette source\, ce qui a permis d’obtenir pour la première fois une puce magnétique à réseau\, capable de générer des atomes ultra-froids. URL:https://fermi.univ-tlse3.fr/event/source-datomes-ultra-froids-pour-les-capteurs-quantiques-embarques-conception-et-mise-en-oeuvre-dune-puce-magnetique-a-reseau/ LOCATION:Salle de conférence\, Bâtiment 3R4 CATEGORIES:Events,HDR / Thesis,LCAR END:VEVENT BEGIN:VEVENT DTSTART;TZID=Europe/Paris:20241018T100000 DTEND;TZID=Europe/Paris:20241018T130000 DTSTAMP:20260413T223644 CREATED:20241016T091215Z LAST-MODIFIED:20241017T064409Z UID:11035-1729245600-1729256400@fermi.univ-tlse3.fr SUMMARY:Thermomigration à l’échelle nanométrique. - (Aurélien Roux / CEMES / These). - 18/10/2024\, 10H00 DESCRIPTION:Soutenance de thèse \nAurélien Roux\, CEMES\, salle de conférence \nCompositition du jury: \n\n\nM. Stefano CURIOTTO – Chargé de recherche\, CINAM (Marseille) (Rapporteur)\nM. Samy MERABIA – Directeur de recherche\, ILM (Lyon) (Rapporteur)\nMme Anne HEMERICK – Directrice de recherche\, LAAS (Toulouse)(Examinatrice)\nM. David LACROIX – Professeur des universités\, LEMTA (Nancy) (Examinateur)\nM. Alois WÜRGER – Professeur des universités\, LOMA (Bordeaux) (Examinateur)\nM. Nicolas COMBE Professeur des universités\, CEMES (Toulouse) (Directeur de thèse) URL:https://fermi.univ-tlse3.fr/event/thermomigration-a-lechelle-nanometrique-aurelien-roux-cemes-these-18-10-2024-10h00/ LOCATION:salle de conférence du CEMES\, CEMES - 29\, rue Jeanne Marvig BP 94347\, Toulouse\, 31055\, France CATEGORIES:CEMES,Events,HDR / Thesis END:VEVENT BEGIN:VEVENT DTSTART;TZID=Europe/Paris:20241022T090000 DTEND;TZID=Europe/Paris:20241022T120000 DTSTAMP:20260413T223644 CREATED:20241015T115919Z LAST-MODIFIED:20241017T120059Z UID:11072-1729587600-1729598400@fermi.univ-tlse3.fr SUMMARY:Modélisation des interactions intermoléculaires dans des milieux complexes issus de la biomasse verte en vue du développement de procédés de filtration membranaire innovants pour l'obtention de biomolécules d'intérêt. - (Marie Certiat / LPCNO/ Thèse). - 22/10/2024\, 9H DESCRIPTION:Soutenance de thèse \nMarie Certiat\, LPCNO\, campus de l’INSA\, au TBI en salle 401 (4ème étage)\nRésumé:\nLes polyphénols\, molécules bioactives d’intérêt\, peuvent être récupérés des jus issus de la biomasse verte par filtration membranaire. Ce procédé prometteur a néanmoins pour limitation principale le colmatage des membranes. Cette thèse s’est concentrée sur l’étude des interactions dans des systèmes combinant une membrane d’ultrafiltration en polyéthersulfone (PES) et des acides tanniques (TA)\, à l’aide de simulations de dynamique moléculaire (MD) classique. De plus\, la modélisation d’une membrane poreuse en PES a permis d’examiner le passage des TA à travers la membrane\, grâce à des simulations MD hors-équilibre\, modélisant le procédé de filtration. Les mécanismes d’adsorption et d’agrégation des TA ont ainsi pu être caractérisés\, mettant en évidence une compétition entre ces deux phénomènes. Par ailleurs\, la formation de ponts cationiques favorisant l’agrégation des TA a été observée suite à l’augmentation du pH ou à l’ajout de sels\, soulignant l’influence des conditions opératoires sur la structure des agrégats et leur adsorption sur la membrane. \nDirection :\n\nFranck Jolibois\nStéphanie Laborie\n\n\n\nEncadrement :\n\nJohanne Teychené\nChristelle Guigui\n\n\n\n\nJury :\n\nM. Anthony SZYMCZYK\, Université de Rennes 1\nM. Philippe GUILBAUD\, CEA – Centre d’Etudes de Marcoule\nMme Christel CAUSSERAND\, Université Toulouse III – Paul Sabatier\nMme Céline PONCET-LEGRAND\, INRAE Montpellier\nM. Christophe RAYNAUD\, Université de Montpellier\nM. Franck JOLIBOIS\,  Université Toulouse III – Paul Sabatier\nMme Stéphanie LABORIE-MENTON\, INSA Toulouse\nMme Johanne TEYCHENE\, INSA Toulouse\nMme Christelle GUIGUI\, INSA Toulouse URL:https://fermi.univ-tlse3.fr/event/modelisation-des-interactions-intermoleculaires-dans-des-milieux-complexes-issus-de-la-biomasse-verte-en-vue-du-developpement-de-procedes-de-filtration-membranaire-innovants-pour-lobtention-de-biomo/ CATEGORIES:Events,HDR / Thesis,LPCNO END:VEVENT BEGIN:VEVENT DTSTART;TZID=Europe/Paris:20241024T140000 DTEND;TZID=Europe/Paris:20241024T170000 DTSTAMP:20260413T223644 CREATED:20241024T074043Z LAST-MODIFIED:20241024T111739Z UID:11040-1729778400-1729789200@fermi.univ-tlse3.fr SUMMARY:Vers une description précise des matériaux spin-orbite fortement corrélés: des modèles aux premiers calculs layered-dmft pour ba2iro4\, sr2iro4 et ba2rho4. - (Léo Gaspard / LCPQ / Thesis). - 24/10/2024\, 14H DESCRIPTION:Soutenance de thèse \nLéo Gaspard\, LCPQ\, Salle de Conférence FeRMI 3R4 \nAbstract:\nThe interest in spin-orbit correlated materials dates back to 1994 when Strontium Ruthenate Sr2RuO4 was shown to exhibit a superconductive behavior. This discovery reignited the interest of the scientific community toward Ruthenates\, but also toward Iridates which share a similar crystallographic structure. Moreover\, in the valence bands of Iridates\, the bandwidth\, the Coulomb interaction and the spin-orbit interaction are all within the same order of magnitude\, forcing their theoretical studies to consider these three effects on an equal footing. In this thesis\, we study the electronic structure of Ba2IrO4\, Sr2IrO4 and Ba2RhO4 . We carefully examine the parametrization and of the models that describe their low-energy spectrum and their resolution using Dynamical Mean Field Theory (DMFT).\nWe first present a downfolding procedure that allows to build physically relevant models for correlated materials and apply it to the aforementioned materials. We then perform the first five-band DMFT calculations on these materials\, showing that the effect of the correlation on the eg bands of these systems is simply a Hartree shift. Finally\, we devise a new method that we call layered-DMFT (L-DMFT)\, which allows to split the correlated space of the five-band model in a part that we treat with a high-precision method and a part that is treated at the mean-field level. We show that this new method yields qualitatively and quantitatively the same results as the complete DMFT method\, while making the calculations up to a hundred times faster. \n\n \n \n  URL:https://fermi.univ-tlse3.fr/event/vers-une-description-precise-des-materiaux-spin-orbite-fortement-correles-des-modeles-aux-premiers-calculs-layered-dmft-pour-ba2iro4-sr2iro4-et-ba2rho4-leo-gaspard-lcpq-thesis-24-10-2024/ LOCATION:Salle de conférence\, Bâtiment 3R4 CATEGORIES:Events,HDR / Thesis,LCPQ END:VEVENT BEGIN:VEVENT DTSTART;TZID=Europe/Paris:20241025T140000 DTEND;TZID=Europe/Paris:20241025T170000 DTSTAMP:20260413T223644 CREATED:20241023T064253Z LAST-MODIFIED:20241024T111732Z UID:11065-1729864800-1729875600@fermi.univ-tlse3.fr SUMMARY:Monte Carlo investigations of Dirac and chiral spin liquids. - (Sasank Budaraju / LPT / Thesis). - 25/10/2024\, 14H DESCRIPTION:Thesis defense \nSasank Budaraju\, LPT\, 3R4 Fermi Seminar room \nAbstract: \nQuantum Spin Liquids (QSLs) are exotic states of matter characterized by their many-body quantum entanglement and emergent fractionalized excitations\, whose low energy physics is described using gauge theories. The experimental realization of QSLs in crystalline materials and their existence as stable ground states in spin models have been fundamental and widely studied questions in condensed matter physics in recent years. \nIn this thesis\, we employ quantum Monte Carlo simulations to investigate two questions related to QSLs in two dimensions: one focused on gapped spin liquids and the other on gapless spin liquids. The first question concerns whether Projected Entangled Pair States (PEPS\, a type of Tensor Network) can accurately represent Chiral Spin Liquids (CSL). Questions have been raised due to a no-go theorem preventing free fermion PEPS representations of chiral non-interacting states. We construct fermionic PEPS (fPEPS) approximants of Gutzwiller-projected Chern insulators (a type of CSL)\, and demonstrate that fPEPS (of finite bond dimension) can capture the correct topological ground-state degeneracy of the CSL. Further\, more general fPEPS are optimized to describe the CSL phase of a frustrated Heisenberg antiferromagnet\, and the chiral edge modes in the entanglement spectrum are shown to follow the predictions from conformal field theory. Consequently\, our work provides additional supporting evidence that PEPS can effectively\nrepresent CSL phases. \nThe second question focuses on the nature of low-energy excitations in gapless Dirac Spin Liquids (DSLs)\, which\, unlike gapped spin liquids\, lack well-defined fractionalized quasiparticle excitations. Since mean-field descriptions of DSLs may not fully capture their behavior\, it is crucial to account for gauge fluctuations beyond the mean-field level. Additionally\, the stability of DSLs as ground states in frustrated Heisenberg antiferromagnets remains an unsettled question. In this work\, we construct variational ansatzes for low-energy excitations of DSLs. Our results indicate that Heisenberg models on triangular and Kagome lattices support gapless monopole and spinon excitations even after Gutzwiller projection. We further demonstrate that the Dirac spin liquid is energetically stable against the formation of chiral spin liquid states generated by multiple monopole insertions. Moreover\, we analyze the momentum quantum numbers of the monopoles\, comparing the states before and after projection. Finally\, we construct flux excitations localized on (pairs of) individual plaquettes. They are gapped in the thermodynamic limit as expected\, but surprisingly have comparable (or even lower) energy than the monopoles for small clusters. Through these results\, we provide incremental insights in understanding the low energy excitations of U(1) spin liquids in two dimensions. \n\n \n \n  URL:https://fermi.univ-tlse3.fr/event/monte-carlo-investigations-of-dirac-and-chiral-spin-liquids-sasank-budaraju-lpt-thesis-25-10-2024-14h/ LOCATION:Salle de conférence\, Bâtiment 3R4 CATEGORIES:Events,HDR / Thesis,LPT END:VEVENT BEGIN:VEVENT DTSTART;TZID=Europe/Paris:20241029T090000 DTEND;TZID=Europe/Paris:20241029T120000 DTSTAMP:20260413T223644 CREATED:20241022T111617Z LAST-MODIFIED:20241024T111757Z UID:11107-1730192400-1730203200@fermi.univ-tlse3.fr SUMMARY:Highly Accurate Computational Strategies for Molecular Electronic States. - (Yann Damour / LCPQ / Thèse). - 29/10/2024\, 9H00 DESCRIPTION:Soutenance de thèse \nYann Damour LCPQ\, Salle de conférence\, 3R4 \nSummary:\nMolecules play an important role in ourlives by surrounding us and participating in a multitude of processes. Most of these processes can be studied experimentally. However\, obstacles can be encountered\, such as the complexity or timescale of the process of interest\, the experimental conditions and their elevated cost\, the presence of dangerous chemicals\, and so on. Theoretical chemistry offers a solution to these problems through numerical simulations. Unfortunately\, the accuracy of these simulations is limited by computational capabilities. This requires approximations to be made\, which can reduce the quality of the obtained results unless managed carefully. Therefore\, reliable reference values are essential for benchmarking these simulations. In this context\, this thesis aims to develop highly-accurate theoretical methods for providing reference values\, focusing on wave function methods such as selected configuration interaction and coupled cluster.\nWe explore different theoretical approaches and various kinds of molecular electronic states. We start with the ground state of medium-sized molecules described with orbital optimized selected configuration interaction (SCI)\, followed by the study of molecular properties of ground and excited states\, also using SCI. Then\, we delve into the continuum with an adaptation of SCI for electronic resonances. After that\, we study the performance of approximate coupled cluster methods with a state-specific approach to compute excitation energies\, before finally proposing a stochastic approach to CCSD(T)\, the gold standard method of quantum chemistry. \n\n \n \n  URL:https://fermi.univ-tlse3.fr/event/highly-accurate-computational-strategies-for-molecular-electronic-states-yann-damour-lcpq-these-29-10-2024-9h00/ LOCATION:Salle de conférence\, Bâtiment 3R4 CATEGORIES:Events,HDR / Thesis,LCPQ END:VEVENT END:VCALENDAR