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13 results on '"Mesple, Florie"'

1. Visualizing the microscopic origins of topology in twisted molybdenum ditelluride

Author

Thompson, Ellis, Chu, Keng Tou, Mesple, Florie, Zhang, Xiao-Wei, Hu, Chaowei, Zhao, Yuzhou, Park, Heonjoon, Cai, Jiaqi, Anderson, Eric, Watanabe, Kenji, Taniguchi, Takashi, Yang, Jihui, Chu, Jiun-Haw, Xu, Xiaodong, Cao, Ting, Xiao, Di, and Yankowitz, Matthew

Subjects
Condensed Matter - Mesoscale and Nanoscale Physics
Abstract

In moir\'e materials with flat electronic bands and suitable quantum geometry, strong correlations can give rise to novel topological states of matter. The nontrivial band topology of twisted molybdenum ditelluride (tMoTe$_2$) -- responsible for its fractional quantum anomalous Hall (FQAH) states -- is predicted to arise from a layer-pseudospin skyrmion lattice. Tracing the layer polarization of wavefunctions within the moir\'e unit cell can thus offer crucial insights into the band topology. Here, we use scanning tunneling microscopy and spectroscopy (STM/S) to probe the layer-pseudospin skyrmion textures of tMoTe$_2$. We do this by simultaneously visualizing the moir\'e lattice structure and the spatial localization of its electronic states. We find that the wavefunctions associated with the topological flat bands exhibit a spatially-dependent layer polarization within the moir\'e unit cell. This is in excellent agreement with our theoretical modeling, thereby revealing a direct microscopic connection between the structural properties of tMoTe$_2$ and its band topology. Our work enables new pathways for engineering FQAH states with strain, as well as future STM studies of the intertwined correlated and topological states arising in gate-tunable devices., Comment: 7 pages, 4 figures, Extended Data, 9 figures, Supplementary Information, 8 pages, 5 figures

Published
2024

2. Magnetic evolution of Cr$_2$Te$_3$ epitaxially grown on graphene with post-growth annealing

Author

Guillet, Quentin, Boukari, Hervé, Choueikani, Fadi, Ohresser, Philippe, Ouerghi, Abdelkarim, Mesple, Florie, Renard, Vincent T., Jacquot, Jean-François, Jalabert, Denis, Vergnaud, Céline, Bonell, Frédéric, Marty, Alain, and Jamet, Matthieu

Subjects
Condensed Matter - Materials Science
Abstract

Two-dimensional and van der Waals ferromagnets are ideal platform to study low dimensional magnetism and proximity effects in van der Waals heterostructures. Their ultimate two dimensional character offers also the opportunity to easily adjust their magnetic properties using strain or electric fields. Among 2D ferromagnets, the Cr$_{1+x}$Te$_2$ compounds with $x$=0-1 are very promising because their magnetic properties depend on the amount of self-intercalated Cr atoms between pure CrTe$_2$ layers and the Curie temperature (T$_C$) can reach room temperature for certain compositions. Here, we investigate the evolution of the composition, structural and magnetic properties of thin Cr$_{1.33}$Te$_2$ (Cr$_2$Te$_3$) films epitaxially grown on graphene upon annealing. We observe a transition above 450{\deg}C from the Cr$_{1.33}$Te$_2$ phase with perpendicular magnetic anisotropy and a T$_C$ of 180 K to a composition close to Cr$_{1.39}$Te$_2$ with in-plane magnetic anisotropy and a T$_C$ of 240-250 K. This phase remains stable up to 650{\deg}C above which a pure Cr film starts to form. This work demonstrates the complex interplay between intercalated Cr, lattice parameters and magnetic properties in Cr$_{1+x}$Te$_2$ compounds., Comment: 5 pages, 5 figures

Published
2024

3. Epitaxial van der Waals heterostructures of Cr2Te3 on 2D materials

Author

Guillet, Quentin, Vojacek, Libor, Dosenovic, Djordje, Ibrahim, Fatima, Boukari, Herve, Li, Jing, Choueikani, Fadi, Ohresser, Philippe, Ouerghi, Abdelkarim, Mesple, Florie, Renard, Vincent, Jacquot, Jean-Francois, Jalabert, Denis, Okuno, Hanako, Chshiev, Mairbek, Vergnaud, Celine, Bonell, Frederic, Marty, Alain, and Jamet, Matthieu

Subjects
Condensed Matter - Materials Science
Abstract

Achieving large-scale growth of two-dimensional (2D) ferromagnetic materials with high Curie temperature (TC) and perpendicular magnetic anisotropy (PMA) is highly desirable for the development of ultra-compact magnetic sensors and magnetic memories. In this context, van der Waals (vdW) Cr2Te3 appears as a promising candidate. Bulk Cr2Te3 exhibits strong PMA and a TC of 180 K. Moreover, both PMA and TC might be adjusted in ultrathin films by engineering composition, strain, or applying an electric field. In this work, we demonstrate the molecular beam epitaxy (MBE) growth of vdW heterostructures of five-monolayer quasi-freestanding Cr2Te3 on three classes of 2D materials: graphene (semimetal), WSe2 (semiconductor) and Bi2Te3 (topological insulator). By combining structural and chemical analysis down to the atomic level with ab initio calculations, we confirm the single crystalline character of Cr2Te3 films on the 2D materials with sharp vdW interfaces. They all exhibit PMA and TC close to the bulk Cr2Te3 value of 180 K. Ab initio calculations confirm this PMA and show how its strength depends on strain. Finally, Hall measurements reveal a strong anomalous Hall effect, which changes sign at a given temperature. We theoretically explain this effect by a sign change of the Berry phase close to the Fermi level. This transition temperature depends on the 2D material in proximity, notably as a consequence of charge transfer. MBE-grown Cr2Te3/2D material bilayers constitute model systems for the further development of spintronic devices combining PMA, large spin-orbit coupling and sharp vdW interface., Comment: 18 pages, 13 figures and Supplemental Material

Published
2023

4. Magnetic evolution of Cr2Te3 epitaxially grown on graphene with post-growth annealing

Author

Guillet, Quentin, primary, Boukari, Hervé, additional, Choueikani, Fadi, additional, Ohresser, Philippe, additional, Ouerghi, Abdelkarim, additional, Mesple, Florie, additional, Renard, Vincent T., additional, Jacquot, Jean-François, additional, Jalabert, Denis, additional, Vergnaud, Céline, additional, Bonell, Frédéric, additional, Marty, Alain, additional, and Jamet, Matthieu, additional

Published
2024
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5. Giant Atomic Swirl in Graphene Bilayers with Biaxial Heterostrain

Author

Mesple, Florie, primary, Walet, Niels R., additional, Trambly de Laissardière, Guy, additional, Guinea, Francisco, additional, Došenović, Djordje, additional, Okuno, Hanako, additional, Paillet, Colin, additional, Michon, Adrien, additional, Chapelier, Claude, additional, and Renard, Vincent T., additional

Published
2023
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6. Magnetic evolution of Cr2Te3 epitaxially grown on graphene with post-growth annealing.

Author

Guillet, Quentin, Boukari, Hervé, Choueikani, Fadi, Ohresser, Philippe, Ouerghi, Abdelkarim, Mesple, Florie, Renard, Vincent T., Jacquot, Jean-François, Jalabert, Denis, Vergnaud, Céline, Bonell, Frédéric, Marty, Alain, and Jamet, Matthieu

Subjects
PERPENDICULAR magnetic anisotropy, MAGNETIC traps, MAGNETIC anisotropy, MAGNETIC properties, GRAPHENE
Abstract

Two-dimensional and van der Waals ferromagnets are ideal platform to study low-dimensional magnetism and proximity effects in van der Waals heterostructures. Their ultimate two-dimensional character also offers the opportunity to easily adjust their magnetic properties using strain or electric fields. Among 2D ferromagnets, the Cr 1 + x Te2 compounds with x = 0–1 are very promising because their magnetic properties depend on the amount of self-intercalated Cr atoms between pure CrTe2 layers and the Curie temperature ( T C ) can reach room temperature for certain compositions. Here, we investigate the evolution of the composition as well as the structural and magnetic properties of thin Cr1.33Te2 (Cr2Te3) films epitaxially grown on graphene upon annealing. We observe a transition above 450 °C from the Cr1.33Te2 phase with perpendicular magnetic anisotropy and a T C of 180 K to a composition close to Cr 1.39 Te2 with in-plane magnetic anisotropy and a T C of 240–250 K. This phase remains stable up to 650 °C above which a pure Cr film starts to form. This work demonstrates the complex interplay between intercalated Cr, lattice parameters, and magnetic properties in Cr 1 + x Te2 compounds. [ABSTRACT FROM AUTHOR]

Published
2024
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7. Atomic‐Layer Controlled Transition from Inverse Rashba–Edelstein Effect to Inverse Spin Hall Effect in 2D PtSe2 Probed by THz Spintronic Emission.

Author

Abdukayumov, Khasan, Mičica, Martin, Ibrahim, Fatima, Vojáček, Libor, Vergnaud, Céline, Marty, Alain, Veuillen, Jean‐Yves, Mallet, Pierre, de Moraes, Isabelle Gomes, Dosenovic, Djordje, Gambarelli, Serge, Maurel, Vincent, Wright, Adrien, Tignon, Jérôme, Mangeney, Juliette, Ouerghi, Abdelkarim, Renard, Vincent, Mesple, Florie, Li, Jing, and Bonell, Frédéric

Published
2024
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8. Epitaxial van der Waals heterostructures of Cr2Te3 on two-dimensional materials

Author

Guillet, Quentin, primary, Vojáček, Libor, additional, Dosenovic, Djordje, additional, Ibrahim, Fatima, additional, Boukari, Hervé, additional, Li, Jing, additional, Choueikani, Fadi, additional, Ohresser, Philippe, additional, Ouerghi, Abdelkarim, additional, Mesple, Florie, additional, Renard, Vincent, additional, Jacquot, Jean-François, additional, Jalabert, Denis, additional, Okuno, Hanako, additional, Chshiev, Mairbek, additional, Vergnaud, Céline, additional, Bonell, Frédéric, additional, Marty, Alain, additional, and Jamet, Matthieu, additional

Published
2023
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9. Epitaxial van der Waals heterostructures of Cr 2 Te 3 on two-dimensional materials

Author

Guillet, Quentin, Vojáček, Libor, Dosenovic, Djordje, Ibrahim, Fatima, Boukari, Hervé, Li, Jing, Choueikani, Fadi, Ohresser, Philippe, Ouerghi, Abdelkarim, Mesple, Florie, Renard, Vincent, Jacquot, Jean-François, Jalabert, Denis, Okuno, Hanako, Chshiev, Mairbek, Vergnaud, Céline, Bonell, Frédéric, Marty, Alain, Jamet, Matthieu, SPINtronique et TEchnologie des Composants (SPINTEC), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA), Modélisation et Exploration des Matériaux (MEM), Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Nanophysique et Semiconducteurs (NEEL - NPSC), Institut Néel (NEEL), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA), Commissariat à l'énergie atomique et aux énergies alternatives - Laboratoire d'Electronique et de Technologie de l'Information (CEA-LETI), Direction de Recherche Technologique (CEA) (DRT (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Synchrotron SOLEIL (SSOLEIL), Centre National de la Recherche Scientifique (CNRS), Centre de Nanosciences et de Nanotechnologies (C2N), Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Transport Electronique Quantique et Supraconductivité (LaTEQS), PHotonique, ELectronique et Ingénierie QuantiqueS (PHELIQS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), SYstèmes Moléculaires et nanoMatériaux pour l’Energie et la Santé (SYMMES), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Microbiologie Environnementale et Moléculaire (MEM), Institut de Biosciences et Biotechnologies d'Aix-Marseille (ex-IBEB) (BIAM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Institut Universitaire de France (IUF), and Ministère de l'Education nationale, de l’Enseignement supérieur et de la Recherche (M.E.N.E.S.R.)

Subjects
[PHYS]Physics [physics], [SPI]Engineering Sciences [physics]
Abstract

International audience; Abstract The recent discovery of superconductivity in paramagnetic UTe 2 turns spotlight on a serious candidate for spin-triplet state. To draw a complete picture of the superconducting state in UTe 2 precise knowledge of the electronic properties of the 5 f states of Uranium is missing. We report on x-ray absorption and magnetic circular dichroism experiments performed at the U M 4,5 edges at 2.7 K. At ambient pressure the 5 f electron count is found to be in-between 2.6 and 2.8. Partial delocalization of the 5 f electrons is further confirmed by the reduced value of the U orbital to spin magnetic moment ratio. The 5 f count is reduced by as large as 7 percent at the transition to a magnetically ordered state at P c ≈ 1.5 GPa. At pressures above 4 GPa, the 5 f count increases back towards U 3+ in the tetragonal phase. The observed “valence instabilities” and their interplay with magnetism seem to be important ingredients to understand the electronic structure in UTe 2 in different phases.

Published
2023
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10. Etude expérimentale des hétérodéformations dans les moirés des bicouches de graphène

Author

Mesple, Florie, PHotonique, ELectronique et Ingénierie QuantiqueS (PHELIQS), Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA), Université Grenoble Alpes [2020-....], Vincent Renard, and Claude Chapelier

Subjects
Heterostrain, [PHYS.PHYS]Physics [physics]/Physics [physics], Bicouches de graphene tournées, Twisted Bilayers of Graphene, Scanning tunneling microscopy, Hétérodéformations, Microscopie à effet tunnel
Abstract

Stacking two layers of graphene on top of each other with a twist gives rise to a moiré pattern. The latter does not affect the linear dispersion of the charge carrier, but renormalises their Fermi velocity. The latter even cancels for an so called magic angle, triggering a new type of electron localisation which is induced by the moiré. This localisation gives rise to strongly correlated phases, such as the recently discovered superconducting phase that created intense interest in the condensed matter community.In this thesis, we investigate the effect of the relative stacking between the layers on the electronic properties of the system. By using Scanning Tunneling Microscopy and Spectroscopy data from the literature we show that the relative strain between the layers, so called heterostrain, controls the physics of twisted bilayers of graphene near the superconducting twist angle regime. The exact stacking arrangement including heterostrain is enough to explain the sample to sample variability that has been observed in recent experiments.At lower angles, in addition to the exact stacking arrangement, local deformations related to relaxation processes of the system on the atomic scale must be taken into account as well. We investigate a new type of moiré induced by biaxial heterodeformations, in which occurs a peculiar relaxation mode that we call a swirl relaxation pattern.Last, aiming at using strain as a tool, we show the building and testing of a strain cell compatible with an Scanning Tunnaling Microscope that operates at room and cryogenic temperatures. Such a device can be used on a variety of materials in addition to twisted graphene layers.; Superposer deux couches de graphène l’une sur l’autre avec une rotation donne lieu à la formation d’un moiré. Ce moiré conserve la dispersion linéaire des porteurs de charge mais leur vitesse de Fermi est renormalisée. Celle-ci s’annule même pour un angle dit magique, donnant lieu à un nouveau type de localisation des électrons, induite par le moiré. Cette dernière donne lieu à la formation de phases fortement corrélées telles que la phase supraconductrice découverte récemment et qui a soulevé un grand intérêt dans la communauté de la matière condensée.Dans cette thèse, on s’intéresse à l’effet de l’empilement relatif entre les couches sur les propriétés électroniques du système.En utilisant des données de microscopie et spectroscopie à effet tunnel, on montre que les déformations relatives entre les couches, nommées hétérodéformations, contrôlent la physique des bicouches de graphène tournées d’un angle proche de l’angle magique. L’arrangement exact entre les couches, comprenant les hétérodéformations, est suffisant pour expliquer la variabilité des proprétés électroniques observées expérimentalement d’un échantillon à l’autre.A plus petit angles encore, il est nécessaire de prendre en compte les déformations locales liées à la relaxation du système à l’échelle atomique. On s’intéresse à un nouveau type moiré dans les bicouches de graphène relaxées, induit par les hétérodéformations biaxiales et dans lequel se développe un mode de relaxation particulier que l’on nomme tourbillon.Enfin, dans le but d’utiliser les déformations comme une sonde, on présente la fabrication et les tests d’une cellule de déformation compatible avec un STM qui opère à température ambiante ou cryogénique. Un tel appareil peut être utilisé sur toute une variété de matériaux, dont les bicouches de graphène tournées.

Published
2022

12. Heterostrain rules the flat-bands in magic-angle twisted graphene layers

Author

Mesple, Florie, Missaoui, Ahmed, Cea, Tommaso, Huder, Loic, Trambly De Laissardière, Guy, Guinea, Francesco, Chapelier, Claude, Renard, Vincent, Laboratoire de Transport Electronique Quantique et Supraconductivité (LaTEQS), PHotonique, ELectronique et Ingénierie QuantiqueS (PHELIQS), Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA), CY Cergy Paris Université (CY), Instituto Madrileño de Estudios Avanzados (IMDEA), Instituto de Ciencia de Materiales de Madrid (ICMM), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), European Synchrotron Radiation Facility (ESRF), Donostia International Physics Center (DIPC), University of the Basque Country/Euskal Herriko Unibertsitatea (UPV/EHU), Laboratoire de Physique Théorique et Modélisation (LPTM - UMR 8089), and Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY)

Subjects
Condensed Matter - Mesoscale and Nanoscale Physics, Mesoscale and Nanoscale Physics (cond-mat.mes-hall), FOS: Physical sciences, [PHYS.COND.CM-MSQHE]Physics [physics]/Condensed Matter [cond-mat]/Mesoscopic Systems and Quantum Hall Effect [cond-mat.mes-hall]
Abstract

The moir\'e of twisted graphene bilayers can generate flat bands in which charge carriers do not posses enough kinetic energy to escape Coulomb interactions with each other leading to the formation of novel strongly correlated electronic states. This exceptionally rich physics relies on the precise arrangement between the layers.We survey published Scanning Tunnelling Microscope (STM) measurements to prove that near the magic angle, native heterostrain, the relative deformations between the layers, dominates twist in determining the flat bands. This is demonstrated at large doping where electronic correlations have a weak effect and where we also show that tip-induced strain can have a strong influence. In the opposite situation of low doping, we find that electronic correlation further normalize the flat bands in a way that strongly depends on experimental details., Comment: Supplementary information available on request

Published
2020
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13. Atomic-Layer Controlled Transition from Inverse Rashba-Edelstein Effect to Inverse Spin Hall Effect in 2D PtSe 2 Probed by THz Spintronic Emission.

Author

Abdukayumov K, Mičica M, Ibrahim F, Vojáček L, Vergnaud C, Marty A, Veuillen JY, Mallet P, de Moraes IG, Dosenovic D, Gambarelli S, Maurel V, Wright A, Tignon J, Mangeney J, Ouerghi A, Renard V, Mesple F, Li J, Bonell F, Okuno H, Chshiev M, George JM, Jaffrès H, Dhillon S, and Jamet M

Abstract

2D materials, such as transition metal dichalcogenides, are ideal platforms for spin-to-charge conversion (SCC) as they possess strong spin-orbit coupling (SOC), reduced dimensionality and crystal symmetries as well as tuneable band structure, compared to metallic structures. Moreover, SCC can be tuned with the number of layers, electric field, or strain. Here, SCC in epitaxially grown 2D PtSe 2 by THz spintronic emission is studied since its 1T crystal symmetry and strong SOC favor SCC. High quality of as-grown PtSe 2 layers is demonstrated, followed by in situ ferromagnet deposition by sputtering that leaves the PtSe 2 unaffected, resulting in well-defined clean interfaces as evidenced with extensive characterization. Through this atomic growth control and using THz spintronic emission, the unique thickness-dependent electronic structure of PtSe 2 allows the control of SCC. Indeed, the transition from the inverse Rashba-Edelstein effect (IREE) in 1-3 monolayers (ML) to the inverse spin Hall effect (ISHE) in multilayers (>3 ML) of PtSe 2 enabling the extraction of the perpendicular spin diffusion length and relative strength of IREE and ISHE is demonstrated. This band structure flexibility makes PtSe 2 an ideal candidate to explore the underlying mechanisms and engineering of the SCC as well as for the development of tuneable THz spintronic emitters., (© 2024 The Authors. Advanced Materials published by Wiley‐VCH GmbH.)

Published
2024
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