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Liu J, Jiang X, Li X, Ma X, Sun X, Zheng Q, Cui X, Tan S, Zhao J, Wang B. Time- and momentum-resolved image-potential states of 2H-MoS 2 surface. Phys Chem Chem Phys 2021; 23:26336-26342. [PMID: 34787611 DOI: 10.1039/d1cp03527d] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Rydberg-like image potential states (IPSs) form special series surface states on metal and semiconducting surfaces. Here, using time-resolved and momentum-resolved multi-photon photoemission (mPPE), we measured the energy positions, band dispersion, and carrier lifetimes of IPSs at the 2H-MoS2 surface. The energy minima of the IPSs (n = 1 and 2) were located at 0.77 and 0.21 eV below the vacuum level. In addition, the effective masses of these two IPSs are close to the rest mass of the free electron, clearly showing nearly-free-electron character. These properties suggest a good screening effect in the MoS2 parallel to the surface. The multi-photon resonances between the valence band and IPS (n = 1) are observed, showing a k‖-momentum-dependent behavior. Our time-resolved mPPE measurements show that the lifetime of photoexcited electrons in the IPS (n = 1) is about 33 fs.
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Affiliation(s)
- Jianyi Liu
- Hefei National Laboratory for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information & Quantum Physics, CAS Key Laboratory of Strongly-Coupled Quantum Matter Physics, and Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026, China.
| | - Xiang Jiang
- Hefei National Laboratory for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information & Quantum Physics, CAS Key Laboratory of Strongly-Coupled Quantum Matter Physics, and Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026, China.
| | - Xintong Li
- Hefei National Laboratory for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information & Quantum Physics, CAS Key Laboratory of Strongly-Coupled Quantum Matter Physics, and Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026, China.
| | - Xiaochuan Ma
- Hefei National Laboratory for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information & Quantum Physics, CAS Key Laboratory of Strongly-Coupled Quantum Matter Physics, and Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026, China.
| | - Xia Sun
- Hefei National Laboratory for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information & Quantum Physics, CAS Key Laboratory of Strongly-Coupled Quantum Matter Physics, and Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026, China.
| | - Qijing Zheng
- Hefei National Laboratory for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information & Quantum Physics, CAS Key Laboratory of Strongly-Coupled Quantum Matter Physics, and Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026, China.
| | - Xuefeng Cui
- Hefei National Laboratory for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information & Quantum Physics, CAS Key Laboratory of Strongly-Coupled Quantum Matter Physics, and Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026, China.
| | - Shijing Tan
- Hefei National Laboratory for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information & Quantum Physics, CAS Key Laboratory of Strongly-Coupled Quantum Matter Physics, and Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026, China.
| | - Jin Zhao
- Hefei National Laboratory for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information & Quantum Physics, CAS Key Laboratory of Strongly-Coupled Quantum Matter Physics, and Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026, China.
| | - Bing Wang
- Hefei National Laboratory for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information & Quantum Physics, CAS Key Laboratory of Strongly-Coupled Quantum Matter Physics, and Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026, China.
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Calloni A, Bussetti G, Avvisati G, Jagadeesh MS, Pacilè D, Ferretti A, Varsano D, Cardoso C, Duò L, Ciccacci F, Betti MG. Empty electron states in cobalt-intercalated graphene. J Chem Phys 2020; 153:214703. [PMID: 33291906 DOI: 10.1063/5.0021814] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The dispersion of the electronic states of epitaxial graphene (Gr) depends significantly on the strength of the bonding with the underlying substrate. We report on empty electron states in cobalt-intercalated Gr grown on Ir(111), studied by angle-resolved inverse photoemission spectroscopy and x-ray absorption spectroscopy, complemented with density functional theory calculations. The weakly bonded Gr on Ir preserves the peculiar spectroscopic features of the Gr band structure, and the empty spectral densities are almost unperturbed. Upon intercalation of a Co layer, the electronic response of the interface changes, with an intermixing of the Gr π* bands and Co d states, which breaks the symmetry of π/σ states, and a downshift of the upper part of the Gr Dirac cone. Similarly, the image potential of Ir(111) is unaltered by the Gr layer, while a downward shift is induced upon Co intercalation, as unveiled by the image state energy dispersion mapped in a large region of the surface Brillouin zone.
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Affiliation(s)
- Alberto Calloni
- Dipartimento di Fisica, Politecnico di Milano, piazza Leonardo da Vinci 32, I-20133 Milano, Italy
| | - Gianlorenzo Bussetti
- Dipartimento di Fisica, Politecnico di Milano, piazza Leonardo da Vinci 32, I-20133 Milano, Italy
| | - Giulia Avvisati
- Dipartimento di Fisica, Università di Roma "La Sapienza", I-00185 Roma, Italy
| | - Madan S Jagadeesh
- Dipartimento di Fisica, Politecnico di Milano, piazza Leonardo da Vinci 32, I-20133 Milano, Italy
| | - Daniela Pacilè
- Dipartimento di Fisica, Università della Calabria, I-87036 Arcavacata di Rende (Cs), Italy
| | | | | | | | - Lamberto Duò
- Dipartimento di Fisica, Politecnico di Milano, piazza Leonardo da Vinci 32, I-20133 Milano, Italy
| | - Franco Ciccacci
- Dipartimento di Fisica, Politecnico di Milano, piazza Leonardo da Vinci 32, I-20133 Milano, Italy
| | - Maria Grazia Betti
- Dipartimento di Fisica, Università di Roma "La Sapienza", I-00185 Roma, Italy
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Schlenhoff A, Kovařík Š, Krause S, Wiesendanger R. Vacuum Resonance States as Atomic-Scale Probes of Noncollinear Surface Magnetism. PHYSICAL REVIEW LETTERS 2019; 123:087202. [PMID: 31491205 DOI: 10.1103/physrevlett.123.087202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Indexed: 06/10/2023]
Abstract
The reflection of electrons at noncollinear magnetic surfaces is investigated by spin-polarized scanning tunneling microscopy and spectroscopy on unoccupied resonance states located in vacuo. Even for energies up to 20 eV above the Fermi level, the resonance states are found to be spin split, exhibiting the same local spin quantization axis as the underlying spin texture. Mapping the spin-dependent electron phase shift upon reflection at the surface on the atomic scale demonstrates the relevance of all magnetic ground state interactions for the scattering of spin-polarized low-energy electrons.
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Affiliation(s)
- Anika Schlenhoff
- Department of Physics, University of Hamburg, Jungiusstrasse 11A, 20355 Hamburg, Germany
| | - Štěpán Kovařík
- Department of Physics, University of Hamburg, Jungiusstrasse 11A, 20355 Hamburg, Germany
| | - Stefan Krause
- Department of Physics, University of Hamburg, Jungiusstrasse 11A, 20355 Hamburg, Germany
| | - Roland Wiesendanger
- Department of Physics, University of Hamburg, Jungiusstrasse 11A, 20355 Hamburg, Germany
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Achilli S, Cavaliere E, Nguyen TH, Cattelan M, Agnoli S. Growth and electronic structure of 2D hexagonal nanosheets on a corrugated rectangular substrate. NANOTECHNOLOGY 2018; 29:485201. [PMID: 30192742 DOI: 10.1088/1361-6528/aadfd2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Graphene and h-BN are grown by chemical vapor deposition in ultra high vacuum conditions on the Pt(110) surface. Scanning tunneling microscopy measurements and low-energy electron diffraction data indicate that graphene forms a variety of differently oriented incommensurate domains although with a strong preference to align its [Formula: see text] direction with the [Formula: see text] direction of Pt. Meanwhile, h-BN exhibits a c(8 × 10) commensurate superstructure, which presents a high level of defectivity that implies local variation of the periodicity (i.e. mixed c(8 × 10) and c(8 × 12) patches) and the introduction of local defects. The combination of advanced photoemission spectroscopy data (angle-resolved photoemission spectroscopy from the valence band) and ab initio calculations indicates that both 2D materials interact weakly with the substrate: graphene exhibits neutral doping and is morphologically flat, even if it nucleates on the relatively highly corrugated rectangular (110) surface. In the case of h-BN, the interaction is slightly stronger and is characterized by a small electron transfer from surface Pt atoms to nitrogen atoms. The (110) termination of Pt is therefore a quite interesting surface for the growth of 2D materials because given its low symmetry, it may favor the growth of selectively oriented domains but does not affect their pristine electronic properties.
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Affiliation(s)
- Simona Achilli
- Department of Physics, European Theoretical Spectroscopy Facility (ETSF), University of Milano, Via Celoria 16, 20133 Milano, Italy
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Jochmann K, Bernhardt TM. The influence of metal cluster lattices on the screening of image potential state electrons on graphene. J Chem Phys 2018; 149:164706. [DOI: 10.1063/1.5052643] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Kira Jochmann
- Institute of Surface Chemistry and Catalysis, University of Ulm, Albert-Einstein-Allee 47, 89069 Ulm, Germany
| | - Thorsten M. Bernhardt
- Institute of Surface Chemistry and Catalysis, University of Ulm, Albert-Einstein-Allee 47, 89069 Ulm, Germany
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Arafune R, Nakazawa T, Takagi N, Kawai M, Ishida H. Comment on "Rashba Spin-Orbit Coupling in Image Potential States". PHYSICAL REVIEW LETTERS 2016; 117:239701. [PMID: 27982628 DOI: 10.1103/physrevlett.117.239701] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Indexed: 06/06/2023]
Affiliation(s)
- Ryuichi Arafune
- International Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science, 1-1 Namiki, Ibaraki 304-0044, Japan
| | - Takeo Nakazawa
- Department of Advanced Materials Science, Graduate School of Frontier Science, The University of Tokyo, Kashiwa 5-1-5, Chiba 277-8561, Japan
| | - Noriaki Takagi
- Department of Advanced Materials Science, Graduate School of Frontier Science, The University of Tokyo, Kashiwa 5-1-5, Chiba 277-8561, Japan
| | - Maki Kawai
- Department of Advanced Materials Science, Graduate School of Frontier Science, The University of Tokyo, Kashiwa 5-1-5, Chiba 277-8561, Japan
| | - Hiroshi Ishida
- College of Humanities and Sciences, Nihon University, Tokyo 156-8550, Japan
- Center for Materials Research by Information Integration, National Institute for Materials Science, Ibaraki 305-0047, Japan
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Tognolini S, Achilli S, Longetti L, Fava E, Mariani C, Trioni MI, Pagliara S. Tognolini et al. Reply. PHYSICAL REVIEW LETTERS 2016; 117:239702. [PMID: 27982607 DOI: 10.1103/physrevlett.117.239702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Indexed: 06/06/2023]
Affiliation(s)
- S Tognolini
- I-LAMP and Dipartimento di Matematica e Fisica, Università Cattolica, 25121 Brescia, Italy
| | - S Achilli
- Dipartimento di Chimica, Università degli Studi di Milano and CNR-ISTM, via Golgi 19, 20133 Milano, Italy
| | - L Longetti
- Dipartimento di Fisica, CNISM, Università di Roma "La Sapienza", 00185 Roma, Italy
| | - E Fava
- I-LAMP and Dipartimento di Matematica e Fisica, Università Cattolica, 25121 Brescia, Italy
| | - C Mariani
- Dipartimento di Fisica, CNISM, Università di Roma "La Sapienza", 00185 Roma, Italy
| | - M I Trioni
- Dipartimento di Chimica, Università degli Studi di Milano and CNR-ISTM, via Golgi 19, 20133 Milano, Italy
| | - S Pagliara
- I-LAMP and Dipartimento di Matematica e Fisica, Università Cattolica, 25121 Brescia, Italy
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Optically induced effective mass renormalization: the case of graphite image potential states. Sci Rep 2016; 6:35318. [PMID: 27739489 PMCID: PMC5064354 DOI: 10.1038/srep35318] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2016] [Accepted: 09/26/2016] [Indexed: 01/24/2023] Open
Abstract
Many-body interactions with the underlying bulk electrons determine the properties of confined electronic states at the surface of a metal. Using momentum resolved nonlinear photoelectron spectroscopy we show that one can tailor these many-body interactions in graphite, leading to a strong renormalization of the dispersion and linewidth of the image potential state. These observations are interpreted in terms of a basic self-energy model, and may be considered as exemplary for optically induced many-body interactions.
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Krasovskii EE. Spin-orbit coupling at surfaces and 2D materials. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2015; 27:493001. [PMID: 26580290 DOI: 10.1088/0953-8984/27/49/493001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Spin-orbit interaction gives rise to a splitting of surface states via the Rashba effect, and in topological insulators it leads to the existence of topological surface states. The resulting k(//) momentum separation between states with the opposite spin underlies a wide range of new phenomena at surfaces and interfaces, such as spin transfer, spin accumulation, spin-to-charge current conversion, which are interesting for fundamental science and may become the basis for a breakthrough in the spintronic technology. The present review summarizes recent theoretical and experimental efforts to reveal the microscopic structure and mechanisms of spin-orbit driven phenomena with the focus on angle and spin-resolved photoemission and scanning tunneling microscopy.
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Affiliation(s)
- E E Krasovskii
- Departamento de Física de Materiales, Universidad del Pais Vasco UPV/EHU, 20080 San Sebastián/Donostia, Spain. Donostia International Physics Center (DIPC), 20018 San Sebastián/Donostia, Spain. IKERBASQUE, Basque Foundation for Science, 48013 Bilbao, Spain
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