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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, Jamet M. Atomic-Layer Controlled Transition from Inverse Rashba-Edelstein Effect to Inverse Spin Hall Effect in 2D PtSe 2 Probed by THz Spintronic Emission. Adv Mater 2024; 36:e2304243. [PMID: 38160244 DOI: 10.1002/adma.202304243] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2023] [Revised: 11/09/2023] [Indexed: 01/03/2024]
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 PtSe2 by THz spintronic emission is studied since its 1T crystal symmetry and strong SOC favor SCC. High quality of as-grown PtSe2 layers is demonstrated, followed by in situ ferromagnet deposition by sputtering that leaves the PtSe2 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 PtSe2 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 PtSe2 enabling the extraction of the perpendicular spin diffusion length and relative strength of IREE and ISHE is demonstrated. This band structure flexibility makes PtSe2 an ideal candidate to explore the underlying mechanisms and engineering of the SCC as well as for the development of tuneable THz spintronic emitters.
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Affiliation(s)
- Khasan Abdukayumov
- CEA, CNRS, Université Grenoble Alpes, Grenoble INP, IRIG-Spintec, Grenoble, 38000, France
| | - Martin Mičica
- Laboratoire de Physique de l'Ecole Normale Supérieure, ENS, Université PSL, CNRS, Sorbonne Université, Université de Paris, Paris, 75005, France
| | - Fatima Ibrahim
- CEA, CNRS, Université Grenoble Alpes, Grenoble INP, IRIG-Spintec, Grenoble, 38000, France
| | - Libor Vojáček
- CEA, CNRS, Université Grenoble Alpes, Grenoble INP, IRIG-Spintec, Grenoble, 38000, France
| | - Céline Vergnaud
- CEA, CNRS, Université Grenoble Alpes, Grenoble INP, IRIG-Spintec, Grenoble, 38000, France
| | - Alain Marty
- CEA, CNRS, Université Grenoble Alpes, Grenoble INP, IRIG-Spintec, Grenoble, 38000, France
| | - Jean-Yves Veuillen
- CNRS, Université Grenoble Alpes, Grenoble INP-UGA, Institut NéeL, Grenoble, 38000, France
| | - Pierre Mallet
- CNRS, Université Grenoble Alpes, Grenoble INP-UGA, Institut NéeL, Grenoble, 38000, France
| | | | | | - Serge Gambarelli
- CEA, CNRS, IRIG-SYMMES, Université Grenoble Alpes, Grenoble, 38000, France
| | - Vincent Maurel
- CEA, CNRS, IRIG-SYMMES, Université Grenoble Alpes, Grenoble, 38000, France
| | - Adrien Wright
- Laboratoire de Physique de l'Ecole Normale Supérieure, ENS, Université PSL, CNRS, Sorbonne Université, Université de Paris, Paris, 75005, France
| | - Jérôme Tignon
- Laboratoire de Physique de l'Ecole Normale Supérieure, ENS, Université PSL, CNRS, Sorbonne Université, Université de Paris, Paris, 75005, France
| | - Juliette Mangeney
- Laboratoire de Physique de l'Ecole Normale Supérieure, ENS, Université PSL, CNRS, Sorbonne Université, Université de Paris, Paris, 75005, France
| | - Abdelkarim Ouerghi
- CNRS, Centre de Nanosciences et de Nanotechnologies, Université Paris-Saclay, Palaiseau, 91120, France
| | - Vincent Renard
- CEA, IRIG-Pheliqs, Université Grenoble Alpes, Grenoble, 38000, France
| | - Florie Mesple
- CEA, IRIG-Pheliqs, Université Grenoble Alpes, Grenoble, 38000, France
| | - Jing Li
- CEA, Leti, Université Grenoble Alpes, Grenoble, 38000, France
| | - Frédéric Bonell
- CEA, CNRS, Université Grenoble Alpes, Grenoble INP, IRIG-Spintec, Grenoble, 38000, France
| | - Hanako Okuno
- CEA, IRIG-MEM, Université Grenoble Alpes, Grenoble, 38000, France
| | - Mairbek Chshiev
- CEA, CNRS, Université Grenoble Alpes, Grenoble INP, IRIG-Spintec, Grenoble, 38000, France
- Institut Universitaire de France, Paris, 75231, France
| | - Jean-Marie George
- Unité Mixte de Physique, CNRS, Thales, Université Paris-Saclay, Palaiseau, F-91767, France
| | - Henri Jaffrès
- Unité Mixte de Physique, CNRS, Thales, Université Paris-Saclay, Palaiseau, F-91767, France
| | - Sukhdeep Dhillon
- Laboratoire de Physique de l'Ecole Normale Supérieure, ENS, Université PSL, CNRS, Sorbonne Université, Université de Paris, Paris, 75005, France
| | - Matthieu Jamet
- CEA, CNRS, Université Grenoble Alpes, Grenoble INP, IRIG-Spintec, Grenoble, 38000, France
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Cortés-Del Río E, Trivini S, Pascual JI, Cherkez V, Mallet P, Veuillen JY, Cuevas JC, Brihuega I. Shaping Graphene Superconductivity with Nanometer Precision. Small 2023:e2308439. [PMID: 38112230 DOI: 10.1002/smll.202308439] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Revised: 11/23/2023] [Indexed: 12/21/2023]
Abstract
Graphene holds great potential for superconductivity due to its pure 2D nature, the ability to tune its carrier density through electrostatic gating, and its unique, relativistic-like electronic properties. At present, still far from controlling and understanding graphene superconductivity, mainly because the selective introduction of superconducting properties to graphene is experimentally very challenging. Here, a method is developed that enables shaping at will graphene superconductivity through a precise control of graphene-superconductor junctions. The method combines the proximity effect with scanning tunnelling microscope (STM) manipulation capabilities. Pb nano-islands are first grown that locally induce superconductivity in graphene. Using a STM, Pb nano-islands can be selectively displaced, over different types of graphene surfaces, with nanometre scale precision, in any direction, over distances of hundreds of nanometres. This opens an exciting playground where a large number of predefined graphene-superconductor hybrid structures can be investigated with atomic scale precision. To illustrate the potential, a series of experiments are performed, rationalized by the quasi-classical theory of superconductivity, going from the fundamental understanding of superconductor-graphene-superconductor heterostructures to the construction of superconductor nanocorrals, further used as "portable" experimental probes of local magnetic moments in graphene.
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Affiliation(s)
- Eva Cortés-Del Río
- Departamento Física de la Materia Condensada, Universidad Autónoma de Madrid, Madrid, E-28049, Spain
- Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, Madrid, E-28049, Spain
| | | | - José I Pascual
- CIC nanoGUNE-BRTA, Donostia-San Sebastián, 20018, Spain
- Ikerbasque, Basque Foundation for Science, Bilbao, 48013, Spain
| | - Vladimir Cherkez
- Université Grenoble Alpes, CNRS, Institut Néel, Grenoble, F-38400, France
- CNRS, Institut Neel, Grenoble, F-38042, France
| | - Pierre Mallet
- Université Grenoble Alpes, CNRS, Institut Néel, Grenoble, F-38400, France
- CNRS, Institut Neel, Grenoble, F-38042, France
| | - Jean-Yves Veuillen
- Université Grenoble Alpes, CNRS, Institut Néel, Grenoble, F-38400, France
- CNRS, Institut Neel, Grenoble, F-38042, France
| | - Juan C Cuevas
- Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, Madrid, E-28049, Spain
- Departamento Física Teórica de la Materia Condensada, Universidad Autónoma de Madrid, Madrid, E-28049, Spain
- Instituto Nicolás Cabrera, Universidad Autónoma de Madrid, Madrid, E-28049, Spain
| | - Iván Brihuega
- Departamento Física de la Materia Condensada, Universidad Autónoma de Madrid, Madrid, E-28049, Spain
- Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, Madrid, E-28049, Spain
- Instituto Nicolás Cabrera, Universidad Autónoma de Madrid, Madrid, E-28049, Spain
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Cortés-Del Río E, Lado JL, Cherkez V, Mallet P, Veuillen JY, Cuevas JC, Gómez-Rodríguez JM, Fernández-Rossier J, Brihuega I. Observation of Yu-Shiba-Rusinov States in Superconducting Graphene. Adv Mater 2021; 33:e2008113. [PMID: 33890694 DOI: 10.1002/adma.202008113] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 02/26/2021] [Indexed: 06/12/2023]
Abstract
When magnetic atoms are inserted inside a superconductor, the superconducting order is locally depleted as a result of the antagonistic nature of magnetism and superconductivity. Thereby, distinctive spectral features, known as Yu-Shiba-Rusinov states, appear inside the superconducting gap. The search for Yu-Shiba-Rusinov states in different materials is intense, as they can be used as building blocks to promote Majorana modes suitable for topological quantum computing. Here, the first observation of Yu-Shiba-Rusinov states in graphene, a non-superconducting 2D material, and without the participation of magnetic atoms, is reported. Superconductivity in graphene is induced by proximity effect brought by adsorbing nanometer-scale superconducting Pb islands. Using scanning tunneling microscopy and spectroscopy the superconducting proximity gap is measured in graphene, and Yu-Shiba-Rusinov states are visualized in graphene grain boundaries. The results reveal the very special nature of those Yu-Shiba-Rusinov states, which extends more than 20 nm away from the grain boundaries. These observations provide the long-sought experimental confirmation that graphene grain boundaries host local magnetic moments and constitute the first observation of Yu-Shiba-Rusinov states in a chemically pure system.
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Affiliation(s)
- Eva Cortés-Del Río
- Departamento Física de la Materia Condensada, Universidad Autónoma de Madrid, Madrid, E-28049, Spain
| | - Jose Luis Lado
- Department of Applied Physics, Aalto University, Espoo, 02150, Finland
| | - Vladimir Cherkez
- Université Grenoble Alpes, Grenoble, 38000, France
- CNRS, Institut Neel, Grenoble, F-38042, France
| | - Pierre Mallet
- Université Grenoble Alpes, Grenoble, 38000, France
- CNRS, Institut Neel, Grenoble, F-38042, France
| | - Jean-Yves Veuillen
- Université Grenoble Alpes, Grenoble, 38000, France
- CNRS, Institut Neel, Grenoble, F-38042, France
| | - Juan Carlos Cuevas
- Departamento Física Teórica de la Materia Condensada, Universidad Autónoma de Madrid, Madrid, E-28049, Spain
- Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, Madrid, E-28049, Spain
| | - José María Gómez-Rodríguez
- Departamento Física de la Materia Condensada, Universidad Autónoma de Madrid, Madrid, E-28049, Spain
- Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, Madrid, E-28049, Spain
- Instituto Nicolás Cabrera, Universidad Autónoma de Madrid, Madrid, E-28049, Spain
| | - Joaquín Fernández-Rossier
- QuantaLab, International Iberian Nanotechnology Laboratory (INL), Avenida Mestre José Veiga, Braga, 4715-310, Portugal
- Departamento de Física Aplicada, Universidad de Alicante, San Vicente del Raspeig, Alicante, 03690, Spain
| | - Iván Brihuega
- Departamento Física de la Materia Condensada, Universidad Autónoma de Madrid, Madrid, E-28049, Spain
- Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, Madrid, E-28049, Spain
- Instituto Nicolás Cabrera, Universidad Autónoma de Madrid, Madrid, E-28049, Spain
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4
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Mallet P, Chiapello F, Okuno H, Boukari H, Jamet M, Veuillen JY. Bound Hole States Associated to Individual Vanadium Atoms Incorporated into Monolayer WSe_{2}. Phys Rev Lett 2020; 125:036802. [PMID: 32745415 DOI: 10.1103/physrevlett.125.036802] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Accepted: 06/09/2020] [Indexed: 06/11/2023]
Abstract
Doping a two-dimensional semiconductor with magnetic atoms is a possible route to induce magnetism in the material. We report on the atomic structure and electronic properties of monolayer WSe_{2} intentionally doped with vanadium atoms by means of scanning transmission electron microscopy and scanning tunneling microscopy and spectroscopy. Most of the V atoms incorporate at W sites. These V_{W} dopants are negatively charged, which induces a localized bound state located 140 meV above the valence band maximum. The overlap of the electronic potential of two charged V_{W} dopants generates additional in-gap states. Eventually, the negative charge may suppress the magnetic moment on the V_{W} dopants.
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Affiliation(s)
- Pierre Mallet
- Université Grenoble Alpes, Institut Neel, F-38042 Grenoble, France
- CNRS, Institut Neel, F-38042 Grenoble, France
| | - Florian Chiapello
- Université Grenoble Alpes, Institut Neel, F-38042 Grenoble, France
- CNRS, Institut Neel, F-38042 Grenoble, France
| | - Hanako Okuno
- Université Grenoble Alpes, CEA, IRIG-MEM, 38000 Grenoble, France
| | - Hervé Boukari
- Université Grenoble Alpes, Institut Neel, F-38042 Grenoble, France
- CNRS, Institut Neel, F-38042 Grenoble, France
| | - Matthieu Jamet
- Université Grenoble Alpes, CEA, CNRS, Grenoble INP, IRIG-SPINTEC, 38000 Grenoble, France
| | - Jean-Yves Veuillen
- Université Grenoble Alpes, Institut Neel, F-38042 Grenoble, France
- CNRS, Institut Neel, F-38042 Grenoble, France
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5
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Cortés-Del Río E, Mallet P, González-Herrero H, Lado JL, Fernández-Rossier J, Gómez-Rodríguez JM, Veuillen JY, Brihuega I. Quantum Confinement of Dirac Quasiparticles in Graphene Patterned with Sub-Nanometer Precision. Adv Mater 2020; 32:e2001119. [PMID: 32567110 DOI: 10.1002/adma.202001119] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Revised: 05/06/2020] [Indexed: 06/11/2023]
Abstract
Quantum confinement of graphene Dirac-like electrons in artificially crafted nanometer structures is a long sought goal that would provide a strategy to selectively tune the electronic properties of graphene, including bandgap opening or quantization of energy levels. However, creating confining structures with nanometer precision in shape, size, and location remains an experimental challenge, both for top-down and bottom-up approaches. Moreover, Klein tunneling, offering an escape route to graphene electrons, limits the efficiency of electrostatic confinement. Here, a scanning tunneling microscope (STM) is used to create graphene nanopatterns, with sub-nanometer precision, by the collective manipulation of a large number of H atoms. Individual graphene nanostructures are built at selected locations, with predetermined orientations and shapes, and with dimensions going all the way from 2 nm up to 1 µm. The method permits the patterns to be erased and rebuilt at will, and it can be implemented on different graphene substrates. STM experiments demonstrate that such graphene nanostructures confine very efficiently graphene Dirac quasiparticles, both in 0D and 1D structures. In graphene quantum dots, perfectly defined energy bandgaps up to 0.8 eV are found that scale as the inverse of the dot's linear dimension, as expected for massless Dirac fermions.
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Affiliation(s)
- Eva Cortés-Del Río
- Departamento Física de la Materia Condensada, Universidad Autónoma de Madrid, Madrid, E-28049, Spain
| | - Pierre Mallet
- Université Grenoble Alpes, Grenoble, F-38400, France
- CNRS, Institut Néel, Grenoble, F-38042, France
| | - Héctor González-Herrero
- Departamento Física de la Materia Condensada, Universidad Autónoma de Madrid, Madrid, E-28049, Spain
| | - José Luis Lado
- Department of Applied Physics, Aalto University, Aalto, FI-00076, Finland
| | - Joaquín Fernández-Rossier
- QuantaLab, International Iberian Nanotechnology Laboratory (INL), Avenida Mestre José Veiga, Braga, 4715-310, Portugal
- Departamento de Física Aplicada, Universidad de Alicante, San Vicente del Raspeig, Alicante, E-03690, Spain
| | - José María Gómez-Rodríguez
- Departamento Física de la Materia Condensada, Universidad Autónoma de Madrid, Madrid, E-28049, Spain
- Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, Madrid, E-28049, Spain
- Instituto Nicolás Cabrera, Universidad Autónoma de Madrid, Madrid, E-28049, Spain
| | - Jean-Yves Veuillen
- Université Grenoble Alpes, Grenoble, F-38400, France
- CNRS, Institut Néel, Grenoble, F-38042, France
| | - Iván Brihuega
- Departamento Física de la Materia Condensada, Universidad Autónoma de Madrid, Madrid, E-28049, Spain
- Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, Madrid, E-28049, Spain
- Instituto Nicolás Cabrera, Universidad Autónoma de Madrid, Madrid, E-28049, Spain
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6
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Dubey S, Lisi S, Nayak G, Herziger F, Nguyen VD, Le Quang T, Cherkez V, González C, Dappe YJ, Watanabe K, Taniguchi T, Magaud L, Mallet P, Veuillen JY, Arenal R, Marty L, Renard J, Bendiab N, Coraux J, Bouchiat V. Correction to Weakly Trapped, Charged, and Free Excitons in Single-Layer MoS 2 in the Presence of Defects, Strain, and Charged Impurities. ACS Nano 2018; 12:10565-10566. [PMID: 30234967 DOI: 10.1021/acsnano.8b07086] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
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7
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Dau MT, Gay M, Di Felice D, Vergnaud C, Marty A, Beigné C, Renaud G, Renault O, Mallet P, Le Quang T, Veuillen JY, Huder L, Renard VT, Chapelier C, Zamborlini G, Jugovac M, Feyer V, Dappe YJ, Pochet P, Jamet M. Beyond van der Waals Interaction: The Case of MoSe 2 Epitaxially Grown on Few-Layer Graphene. ACS Nano 2018; 12:2319-2331. [PMID: 29384649 DOI: 10.1021/acsnano.7b07446] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Van der Waals heterojunctions composed of graphene and transition metal dichalcogenides have gain much attention because of the possibility to control and tailor band structure, promising applications in two-dimensional optoelectronics and electronics. In this report, we characterized the van der Waals heterojunction MoSe2/few-layer graphene with a high-quality interface using cutting-edge surface techniques scaling from atomic to microscopic range. These surface analyses gave us a complete picture of the atomic structure and electronic properties of the heterojunction. In particular, we found two important results: the commensurability between the MoSe2 and few-layer graphene lattices and a band-gap opening in the few-layer graphene. The band gap is as large as 250 meV, and we ascribed it to an interface charge transfer that results in an electronic depletion in the few-layer graphene. This conclusion is well supported by electron spectroscopy data and density functional theory calculations. The commensurability between the MoSe2 and graphene lattices as well as the band-gap opening clearly show that the interlayer interaction goes beyond the simple van der Waals interaction. Hence, stacking two-dimensional materials in van der Waals heterojunctions enables us to tailor the atomic and electronic properties of individual layers. It also permits the introduction of a band gap in few-layer graphene by interface charge transfer.
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Affiliation(s)
- Minh Tuan Dau
- Université Grenoble Alpes , CEA, CNRS, Grenoble INP, INAC-SPINTEC, 38000 Grenoble , France
| | - Maxime Gay
- Université Grenoble Alpes , CEA, LETI, Minatec Campus, F-38054 Grenoble , France
| | - Daniela Di Felice
- SPEC, CEA, CNRS, Université Paris Saclay , CEA Saclay, 91191 Gif-sur-Yvette Cedex , France
| | - Céline Vergnaud
- Université Grenoble Alpes , CEA, CNRS, Grenoble INP, INAC-SPINTEC, 38000 Grenoble , France
| | - Alain Marty
- Université Grenoble Alpes , CEA, CNRS, Grenoble INP, INAC-SPINTEC, 38000 Grenoble , France
| | - Cyrille Beigné
- Université Grenoble Alpes , CEA, CNRS, Grenoble INP, INAC-SPINTEC, 38000 Grenoble , France
| | - Gilles Renaud
- Université Grenoble Alpes , CEA, INAC, MEM, 38000 Grenoble , France
| | - Olivier Renault
- Université Grenoble Alpes , CEA, LETI, Minatec Campus, F-38054 Grenoble , France
| | - Pierre Mallet
- Université Grenoble Alpes, CNRS, Institut Néel , F-38000 Grenoble , France
| | - Toai Le Quang
- Université Grenoble Alpes, CNRS, Institut Néel , F-38000 Grenoble , France
| | - Jean-Yves Veuillen
- Université Grenoble Alpes, CNRS, Institut Néel , F-38000 Grenoble , France
| | - Loïc Huder
- Université Grenoble Alpes , CEA, INAC, PHELIQS, 38000 Grenoble , France
| | - Vincent T Renard
- Université Grenoble Alpes , CEA, INAC, PHELIQS, 38000 Grenoble , France
| | - Claude Chapelier
- Université Grenoble Alpes , CEA, INAC, PHELIQS, 38000 Grenoble , France
| | - Giovanni Zamborlini
- Peter Grünberg Institute (PGI-6), Forschungszentrum Jülich GmbH , D-52425 , Jülich , Germany
| | - Matteo Jugovac
- Peter Grünberg Institute (PGI-6), Forschungszentrum Jülich GmbH , D-52425 , Jülich , Germany
| | - Vitaliy Feyer
- Peter Grünberg Institute (PGI-6), Forschungszentrum Jülich GmbH , D-52425 , Jülich , Germany
| | - Yannick J Dappe
- SPEC, CEA, CNRS, Université Paris Saclay , CEA Saclay, 91191 Gif-sur-Yvette Cedex , France
| | - Pascal Pochet
- Université Grenoble Alpes , CEA, INAC, MEM, 38000 Grenoble , France
| | - Matthieu Jamet
- Université Grenoble Alpes , CEA, CNRS, Grenoble INP, INAC-SPINTEC, 38000 Grenoble , France
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8
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Dubey S, Lisi S, Nayak G, Herziger F, Nguyen VD, Le Quang T, Cherkez V, González C, Dappe YJ, Watanabe K, Taniguchi T, Magaud L, Mallet P, Veuillen JY, Arenal R, Marty L, Renard J, Bendiab N, Coraux J, Bouchiat V. Weakly Trapped, Charged, and Free Excitons in Single-Layer MoS 2 in the Presence of Defects, Strain, and Charged Impurities. ACS Nano 2017; 11:11206-11216. [PMID: 28992415 DOI: 10.1021/acsnano.7b05520] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Few- and single-layer MoS2 host substantial densities of defects. They are thought to influence the doping level, the crystal structure, and the binding of electron-hole pairs. We disentangle the concomitant spectroscopic expression of all three effects and identify to what extent they are intrinsic to the material or extrinsic to it, i.e., related to its local environment. We do so by using different sources of MoS2-a natural one and one prepared at high pressure and high temperature-and different substrates bringing varying amounts of charged impurities and by separating the contributions of internal strain and doping in Raman spectra. Photoluminescence unveils various optically active excitonic complexes. We discover a defect-bound state having a low binding energy of 20 meV that does not appear sensitive to strain and doping, unlike charged excitons. Conversely, the defect does not significantly dope or strain MoS2. Scanning tunneling microscopy and density functional theory simulations point to substitutional atoms, presumably individual nitrogen atoms at the sulfur site. Our work shows the way to a systematic understanding of the effect of external and internal fields on the optical properties of two-dimensional materials.
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Affiliation(s)
- Sudipta Dubey
- Univ. Grenoble Alpes, CNRS, Grenoble INP, Institut Néel , 38000 Grenoble, France
| | - Simone Lisi
- Univ. Grenoble Alpes, CNRS, Grenoble INP, Institut Néel , 38000 Grenoble, France
| | - Goutham Nayak
- Univ. Grenoble Alpes, CNRS, Grenoble INP, Institut Néel , 38000 Grenoble, France
| | - Felix Herziger
- Univ. Grenoble Alpes, CNRS, Grenoble INP, Institut Néel , 38000 Grenoble, France
| | - Van-Dung Nguyen
- Univ. Grenoble Alpes, CNRS, Grenoble INP, Institut Néel , 38000 Grenoble, France
| | - Toai Le Quang
- Univ. Grenoble Alpes, CNRS, Grenoble INP, Institut Néel , 38000 Grenoble, France
| | - Vladimir Cherkez
- Univ. Grenoble Alpes, CNRS, Grenoble INP, Institut Néel , 38000 Grenoble, France
| | - César González
- SPEC, CEA, CNRS, Université Paris-Saclay, CEA Saclay , 91191 Gif-sur-Yvette Cedex, France
- Departamento de Física Teórica de la Materia Condensada and Condensed Matter Physics Center (IFIMAC), Facultad de Ciencias, Universidad Autonoma de Madrid , E-28049 Madrid, Spain
| | - Yannick J Dappe
- SPEC, CEA, CNRS, Université Paris-Saclay, CEA Saclay , 91191 Gif-sur-Yvette Cedex, France
| | - Kenji Watanabe
- National Institute for Materials Science , Tsukuba, 305-0044, Japan
| | | | - Laurence Magaud
- Univ. Grenoble Alpes, CNRS, Grenoble INP, Institut Néel , 38000 Grenoble, France
| | - Pierre Mallet
- Univ. Grenoble Alpes, CNRS, Grenoble INP, Institut Néel , 38000 Grenoble, France
| | - Jean-Yves Veuillen
- Univ. Grenoble Alpes, CNRS, Grenoble INP, Institut Néel , 38000 Grenoble, France
| | - Raul Arenal
- Laboratorio de Microscopiías Avanzadas, Instituto de Nanociencia de Aragón, Universidad de Zaragoza , 50018 Zaragoza, Spain
- ARAID Foundation , 50018 Zaragoza, Spain
| | - Laëtitia Marty
- Univ. Grenoble Alpes, CNRS, Grenoble INP, Institut Néel , 38000 Grenoble, France
| | - Julien Renard
- Univ. Grenoble Alpes, CNRS, Grenoble INP, Institut Néel , 38000 Grenoble, France
| | - Nedjma Bendiab
- Univ. Grenoble Alpes, CNRS, Grenoble INP, Institut Néel , 38000 Grenoble, France
| | - Johann Coraux
- Univ. Grenoble Alpes, CNRS, Grenoble INP, Institut Néel , 38000 Grenoble, France
| | - Vincent Bouchiat
- Univ. Grenoble Alpes, CNRS, Grenoble INP, Institut Néel , 38000 Grenoble, France
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Tiberj A, Huntzinger JR, Camassel J, Hiebel F, Mahmood A, Mallet P, Naud C, Veuillen JY. Multiscale investigation of graphene layers on 6H-SiC(000-1). Nanoscale Res Lett 2011; 6:171. [PMID: 21711702 PMCID: PMC3211224 DOI: 10.1186/1556-276x-6-171] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/06/2010] [Accepted: 02/24/2011] [Indexed: 05/31/2023]
Abstract
In this article, a multiscale investigation of few graphene layers grown on 6H-SiC(000-1) under ultrahigh vacuum (UHV) conditions is presented. At 100-μm scale, the authors show that the UHV growth yields few layer graphene (FLG) with an average thickness given by Auger spectroscopy between 1 and 2 graphene planes. At the same scale, electron diffraction reveals a significant rotational disorder between the first graphene layer and the SiC surface, although well-defined preferred orientations exist. This is confirmed at the nanometer scale by scanning tunneling microscopy (STM). Finally, STM (at the nm scale) and Raman spectroscopy (at the μm scale) show that the FLG stacking is turbostratic, and that the domain size of the crystallites ranges from 10 to 100 nm. The most striking result is that the FLGs experience a strong compressive stress that is seldom observed for graphene grown on the C face of SiC substrates.
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Affiliation(s)
- Antoine Tiberj
- Groupe d'Etude des Semiconducteurs, UMR5650 CNRS-Université Montpellier II, cc074, Place Eugène Bataillon, 34095 Montpellier Cedex 5, France
| | - Jean-Roch Huntzinger
- Groupe d'Etude des Semiconducteurs, UMR5650 CNRS-Université Montpellier II, cc074, Place Eugène Bataillon, 34095 Montpellier Cedex 5, France
| | - Jean Camassel
- Groupe d'Etude des Semiconducteurs, UMR5650 CNRS-Université Montpellier II, cc074, Place Eugène Bataillon, 34095 Montpellier Cedex 5, France
| | - Fanny Hiebel
- Institut Néel, CNRS-UJF, Boîte Postale 166, 38042 Grenoble Cedex 9, France
| | - Ather Mahmood
- Institut Néel, CNRS-UJF, Boîte Postale 166, 38042 Grenoble Cedex 9, France
| | - Pierre Mallet
- Institut Néel, CNRS-UJF, Boîte Postale 166, 38042 Grenoble Cedex 9, France
| | - Cecile Naud
- Institut Néel, CNRS-UJF, Boîte Postale 166, 38042 Grenoble Cedex 9, France
| | - Jean-Yves Veuillen
- Institut Néel, CNRS-UJF, Boîte Postale 166, 38042 Grenoble Cedex 9, France
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Brihuega I, Mallet P, Bena C, Bose S, Michaelis C, Vitali L, Varchon F, Magaud L, Kern K, Veuillen JY. Quasiparticle chirality in epitaxial graphene probed at the nanometer scale. Phys Rev Lett 2008; 101:206802. [PMID: 19113366 DOI: 10.1103/physrevlett.101.206802] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2008] [Indexed: 05/27/2023]
Abstract
Graphene exhibits unconventional two-dimensional electronic properties resulting from the symmetry of its quasiparticles, which leads to the concepts of pseudospin and electronic chirality. Here, we report that scanning tunneling microscopy can be used to probe these unique symmetry properties at the nanometer scale. They are reflected in the quantum interference pattern resulting from elastic scattering off impurities, and they can be directly read from its fast Fourier transform. Our data, complemented by theoretical calculations, demonstrate that the pseudospin and the electronic chirality in epitaxial graphene on SiC(0001) correspond to the ones predicted for ideal graphene.
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Affiliation(s)
- I Brihuega
- Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, D-70569 Stuttgart, Germany
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Magaud L, Veuillen JY, Lollman D, Papaconstantopoulos DA, Mehl MJ. Electronic structure of ErSi2 and YSi2. Phys Rev B Condens Matter 1992; 46:1299-1304. [PMID: 10003767 DOI: 10.1103/physrevb.46.1299] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Veuillen JY, Bensaoula A, Derrien J. Short-range local order of the Co/Si(111) interface studied by the extended Auger fine-structure technique. Phys Rev B Condens Matter 1989; 39:10398-10401. [PMID: 9947833 DOI: 10.1103/physrevb.39.10398] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Veuillen JY, Nguyn TT, Cinti R, Derrien J. Co/Si(111) interface investigated by bremsstrahlung isochromat spectroscopy and x-ray-induced photoemission spectroscopy. Phys Rev B Condens Matter 1989; 39:8015-8017. [PMID: 9947497 DOI: 10.1103/physrevb.39.8015] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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