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Geisenhof FR, Winterer F, Seiler AM, Lenz J, Zhang F, Weitz RT. Impact of Electric Field Disorder on Broken-Symmetry States in Ultraclean Bilayer Graphene. NANO LETTERS 2022; 22:7378-7385. [PMID: 36113049 DOI: 10.1021/acs.nanolett.2c02119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Bilayer graphene (BLG) has multiple internal degrees of freedom and a constant density of states down to the charge neutrality point when trigonal warping is ignored. Consequently, it is susceptible to various competing ground states. However, a coherent experimental determination of the ground state has been challenging due to the interaction-disorder interplay. Here we present an extensive transport study in a series of dually gated freestanding BLG devices and identify the layer-antiferromagnet as the ground state with a continuous strength across all devices. This strength correlates with the width of the state in the electric field. We systematically identify electric-field disorder─spatial variations in the interlayer potential difference─as the main source responsible for the observations. Our results pinpoint for the first time the importance of electric-field disorder on spontaneous symmetry breaking in BLG and solve a long-standing debate on its ground state. The electric-field disorder should be universal to all 2D materials.
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Affiliation(s)
- Fabian R Geisenhof
- Physics of Nanosystems, Department of Physics, Ludwig-Maximilians-Universität München, Geschwister-Scholl-Platz 1, Munich 80539, Germany
| | - Felix Winterer
- Physics of Nanosystems, Department of Physics, Ludwig-Maximilians-Universität München, Geschwister-Scholl-Platz 1, Munich 80539, Germany
| | - Anna M Seiler
- Physics of Nanosystems, Department of Physics, Ludwig-Maximilians-Universität München, Geschwister-Scholl-Platz 1, Munich 80539, Germany
- 1st Physical Institute, Faculty of Physics, University of Göttingen, Friedrich-Hund-Platz 1, Göttingen 37077, Germany
| | - Jakob Lenz
- Physics of Nanosystems, Department of Physics, Ludwig-Maximilians-Universität München, Geschwister-Scholl-Platz 1, Munich 80539, Germany
| | - Fan Zhang
- Department of Physics, University of Texas at Dallas, Richardson, Texas 75080, United States
| | - R Thomas Weitz
- Physics of Nanosystems, Department of Physics, Ludwig-Maximilians-Universität München, Geschwister-Scholl-Platz 1, Munich 80539, Germany
- Center for Nanoscience (CeNS), Schellingstrasse 4, Munich 80799, Germany
- Munich Center for Quantum Science and Technology (MCQST), Schellingstrasse 4, Munich 80799, Germany
- 1st Physical Institute, Faculty of Physics, University of Göttingen, Friedrich-Hund-Platz 1, Göttingen 37077, Germany
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2
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Interplay between topological valley and quantum Hall edge transport. Nat Commun 2022; 13:4187. [PMID: 35858959 PMCID: PMC9300606 DOI: 10.1038/s41467-022-31680-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Accepted: 06/21/2022] [Indexed: 11/08/2022] Open
Abstract
An established way of realising topologically protected states in a two-dimensional electron gas is by applying a perpendicular magnetic field thus creating quantum Hall edge channels. In electrostatically gapped bilayer graphene intriguingly, even in the absence of a magnetic field, topologically protected electronic states can emerge at naturally occurring stacking domain walls. While individually both types of topologically protected states have been investigated, their intriguing interplay remains poorly understood. Here, we focus on the interplay between topological domain wall states and quantum Hall edge transport within the eight-fold degenerate zeroth Landau level of high-quality suspended bilayer graphene. We find that the two-terminal conductance remains approximately constant for low magnetic fields throughout the distinct quantum Hall states since the conduction channels are traded between domain wall and device edges. For high magnetic fields, however, we observe evidence of transport suppression at the domain wall, which can be attributed to the emergence of spectral minigaps. This indicates that stacking domain walls potentially do not correspond to a topological domain wall in the order parameter.
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3
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Yang SJ, Jung JH, Lee E, Han E, Choi MY, Jung D, Choi S, Park JH, Oh D, Noh S, Kim KJ, Huang PY, Hwang CC, Kim CJ. Wafer-Scale Programmed Assembly of One-Atom-Thick Crystals. NANO LETTERS 2022; 22:1518-1524. [PMID: 35119873 DOI: 10.1021/acs.nanolett.1c04139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Crystalline films offer various physical properties based on the modulation of their thicknesses and atomic structures. The layer-by-layer assembly of atomically thin crystals provides a powerful means to arbitrarily design films at the atomic level, which are unattainable with existing growth technologies. However, atomically clean assembly of the materials with high scalability and reproducibility remains challenging. We report programmed crystal assembly of graphene and monolayer hexagonal boron nitride, assisted by van der Waals interactions, to form wafer-scale films of pristine interfaces with near-unity yield. The atomic configurations of the films are tailored with layer-resolved compositions and in-plane crystalline orientations. We demonstrate batch-fabricated tunnel device arrays with modulation of the resistance over orders of magnitude by thickness control of the hexagonal boron nitride barrier with single-atom precision and large-scale, twisted multilayer graphene with programmable electronic band structures and crystal symmetries. Our results constitute an important development in the artificial design of large-scale films.
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Affiliation(s)
- Seong-Jun Yang
- Department of Chemical Engineering, Pohang University of Science and Technology, Pohang, Gyeongbuk 37673, Republic of Korea
| | - Ju-Hyun Jung
- Department of Chemical Engineering, Pohang University of Science and Technology, Pohang, Gyeongbuk 37673, Republic of Korea
| | - Eunsook Lee
- Beamline Research Division, Pohang Accelerator Laboratory, Pohang, Gyeongbuk 37673, Republic of Korea
| | - Edmund Han
- Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Min-Yeong Choi
- Department of Chemical Engineering, Pohang University of Science and Technology, Pohang, Gyeongbuk 37673, Republic of Korea
| | - Daesung Jung
- Convergence Research Center for Energy and Environmental Sciences, Sungkyunkwan University, Suwon, Gyeonggi 16419, Republic of Korea
| | - Shinyoung Choi
- Department of Chemical Engineering, Pohang University of Science and Technology, Pohang, Gyeongbuk 37673, Republic of Korea
| | - Jun-Ho Park
- Department of Chemical Engineering, Pohang University of Science and Technology, Pohang, Gyeongbuk 37673, Republic of Korea
| | - Dongseok Oh
- Beamline Research Division, Pohang Accelerator Laboratory, Pohang, Gyeongbuk 37673, Republic of Korea
| | - Siwoo Noh
- Beamline Research Division, Pohang Accelerator Laboratory, Pohang, Gyeongbuk 37673, Republic of Korea
| | - Ki-Jeong Kim
- Beamline Research Division, Pohang Accelerator Laboratory, Pohang, Gyeongbuk 37673, Republic of Korea
| | - Pinshane Y Huang
- Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Chan-Cuk Hwang
- Beamline Research Division, Pohang Accelerator Laboratory, Pohang, Gyeongbuk 37673, Republic of Korea
| | - Cheol-Joo Kim
- Department of Chemical Engineering, Pohang University of Science and Technology, Pohang, Gyeongbuk 37673, Republic of Korea
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4
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Cortés N, Negrete O, Peña FJ, Vargas P. Gate-tunable charge carrier electrocaloric effect in trilayer graphene. Sci Rep 2021; 11:22000. [PMID: 34753972 PMCID: PMC8578550 DOI: 10.1038/s41598-021-01057-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Accepted: 10/21/2021] [Indexed: 11/09/2022] Open
Abstract
The electrocaloric (EC) effect is the change in temperature and entropy of a material driven by the application of an electric field. Our tight-binding calculations linked to Fermi statistics, show that the EC effect can be produced in trilayer graphene (TLG) structures connected to a heat source, triggered by changes in the electronic density of states (DOS) at the Fermi level when external gate fields are applied on the outer graphene layers. We demonstrate that entropy changes are sensitive to the stacking arrangement in TLG systems. The AAA-stacked TLG presents an inverse EC response (cooling) regardless of the temperature value and gate field potential strength, whereas the EC effect in ABC-stacked TLG remains direct (heating) above room temperature. We reveal otherwise the TLG with Bernal-ABA stacking generates both the direct and inverse EC response within the same sample, associated with gate-dependent electronic transitions of thermally excited charge carriers from the valence band to the conduction band in the band structure. The novel charge carrier electrocaloric effect we propose in quantum layered systems may bring a wide variety of prototype van der Waals materials that could be used as versatile platforms to controlling the thermal response in nanodevices.
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Affiliation(s)
- Natalia Cortés
- Departamento de Física, Universidad Técnica Federico Santa María, Casilla 110V, Valparaíso, Chile.
| | - Oscar Negrete
- Departamento de Física, Universidad Técnica Federico Santa María, Casilla 110V, Valparaíso, Chile
- Centro para el Desarrollo de la Nanociencia y la Nanotecnología, 8320000, Santiago, Chile
| | - Francisco J Peña
- Departamento de Física, Universidad Técnica Federico Santa María, Casilla 110V, Valparaíso, Chile
| | - Patricio Vargas
- Departamento de Física, Universidad Técnica Federico Santa María, Casilla 110V, Valparaíso, Chile
- Centro para el Desarrollo de la Nanociencia y la Nanotecnología, 8320000, Santiago, Chile
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5
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Geisenhof FR, Winterer F, Seiler AM, Lenz J, Xu T, Zhang F, Weitz RT. Quantum anomalous Hall octet driven by orbital magnetism in bilayer graphene. Nature 2021; 598:53-58. [PMID: 34616059 DOI: 10.1038/s41586-021-03849-w] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Accepted: 07/22/2021] [Indexed: 11/09/2022]
Abstract
The quantum anomalous Hall (QAH) effect-a macroscopic manifestation of chiral band topology at zero magnetic field-has been experimentally realized only by the magnetic doping of topological insulators1-3 and the delicate design of moiré heterostructures4-8. However, the seemingly simple bilayer graphene without magnetic doping or moiré engineering has long been predicted to host competing ordered states with QAH effects9-11. Here we explore states in bilayer graphene with a conductance of 2 e2 h-1 (where e is the electronic charge and h is Planck's constant) that not only survive down to anomalously small magnetic fields and up to temperatures of five kelvin but also exhibit magnetic hysteresis. Together, the experimental signatures provide compelling evidence for orbital-magnetism-driven QAH behaviour that is tunable via electric and magnetic fields as well as carrier sign. The observed octet of QAH phases is distinct from previous observations owing to its peculiar ferrimagnetic and ferrielectric order that is characterized by quantized anomalous charge, spin, valley and spin-valley Hall behaviour9.
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Affiliation(s)
- Fabian R Geisenhof
- Physics of Nanosystems, Department of Physics, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Felix Winterer
- Physics of Nanosystems, Department of Physics, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Anna M Seiler
- Physics of Nanosystems, Department of Physics, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Jakob Lenz
- Physics of Nanosystems, Department of Physics, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Tianyi Xu
- Department of Physics, University of Texas at Dallas, Richardson, TX, USA
| | - Fan Zhang
- Department of Physics, University of Texas at Dallas, Richardson, TX, USA.
| | - R Thomas Weitz
- Physics of Nanosystems, Department of Physics, Ludwig-Maximilians-Universität München, Munich, Germany. .,Center for Nanoscience (CeNS), Munich, Germany. .,Munich Center for Quantum Science and Technology (MCQST), Munich, Germany. .,1st Physical Institute, Faculty of Physics, University of Göttingen, Göttingen, Germany.
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6
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Rycerz A. Wiedemann-Franz Law for Massless Dirac Fermions with Implications for Graphene. MATERIALS (BASEL, SWITZERLAND) 2021; 14:2704. [PMID: 34063902 PMCID: PMC8196567 DOI: 10.3390/ma14112704] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Revised: 05/14/2021] [Accepted: 05/17/2021] [Indexed: 11/16/2022]
Abstract
In the 2016 experiment by Crossno et al. the electronic contribution to the thermal conductivity of graphene was found to violate the well-known Wiedemann-Franz (WF) law for metals. At liquid nitrogen temperatures, the thermal to electrical conductivity ratio of charge-neutral samples was more than 10 times higher than predicted by the WF law, which was attributed to interactions between particles leading to collective behavior described by hydrodynamics. Here, we show, by adapting the handbook derivation of the WF law to the case of massless Dirac fermions, that significantly enhanced thermal conductivity should appear also in few- or even sub-kelvin temperatures, where the role of interactions can be neglected. The comparison with numerical results obtained within the Landauer-Büttiker formalism for rectangular and disk-shaped (Corbino) devices in ballistic graphene is also provided.
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Affiliation(s)
- Adam Rycerz
- Institute for Theoretical Physics, Jagiellonian University, Łojasiewicza 11, PL-30348 Kraków, Poland
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7
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Lee HY, Al Ezzi MM, Raghuvanshi N, Chung JY, Watanabe K, Taniguchi T, Garaj S, Adam S, Gradečak S. Tunable Optical Properties of Thin Films Controlled by the Interface Twist Angle. NANO LETTERS 2021; 21:2832-2839. [PMID: 33591206 DOI: 10.1021/acs.nanolett.0c04924] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Control of materials properties has been the driving force of modern technologies. So far, materials properties have been modulated by their composition, structure, and size. Here, by using cathodoluminescence in a scanning transmission electron microscope, we show that the optical properties of stacked, >100 nm thick hexagonal boron nitride (hBN) films can be continuously tuned by their relative twist angles. Due to the formation of a moiré superlattice between the two interface layers of the twisted films, a new moiré sub-band gap is formed with continuously decreasing magnitude as a function of the twist angle, resulting in tunable luminescence wavelength and intensity increase of >40×. Our results demonstrate that moiré phenomena extend beyond monolayer-based systems and can be preserved in a technologically relevant, bulklike material at room temperature, dominating optical properties of hBN films for applications in medicine, environmental, or information technologies.
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Affiliation(s)
- Hae Yeon Lee
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02141, United States
| | - Mohammed M Al Ezzi
- Department of Physics, National University of Singapore, 2 Science Drive 3, 117542 Singapore
- Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore, 117546 Singapore
| | - Nimisha Raghuvanshi
- Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore, 117546 Singapore
| | - Jing Yang Chung
- Department of Materials Science and Engineering, National University of Singapore, 9 Engineering Drive 1, 117575 Singapore
| | - Kenji Watanabe
- National Institute for Materials Science, Namiki 1-1, Tsukuba, Ibaraki 305-0044, Japan
| | - Takashi Taniguchi
- National Institute for Materials Science, Namiki 1-1, Tsukuba, Ibaraki 305-0044, Japan
| | - Slaven Garaj
- Department of Physics, National University of Singapore, 2 Science Drive 3, 117542 Singapore
- Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore, 117546 Singapore
| | - Shaffique Adam
- Department of Physics, National University of Singapore, 2 Science Drive 3, 117542 Singapore
- Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore, 117546 Singapore
- Yale-NUS College, 16 College Avenue West, 138527 Singapore
| | - Silvija Gradečak
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02141, United States
- Department of Materials Science and Engineering, National University of Singapore, 9 Engineering Drive 1, 117575 Singapore
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8
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Zheng Z, Ma Q, Bi Z, de la Barrera S, Liu MH, Mao N, Zhang Y, Kiper N, Watanabe K, Taniguchi T, Kong J, Tisdale WA, Ashoori R, Gedik N, Fu L, Xu SY, Jarillo-Herrero P. Unconventional ferroelectricity in moiré heterostructures. Nature 2020; 588:71-76. [DOI: 10.1038/s41586-020-2970-9] [Citation(s) in RCA: 77] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Accepted: 10/07/2020] [Indexed: 11/09/2022]
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9
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Nyáry A, Gubicza A, Overbeck J, Pósa L, Makk P, Calame M, Halbritter A, Csontos M. A non-oxidizing fabrication method for lithographic break junctions of sensitive metals. NANOSCALE ADVANCES 2020; 2:3829-3833. [PMID: 36132792 PMCID: PMC9419795 DOI: 10.1039/d0na00498g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Accepted: 07/23/2020] [Indexed: 06/16/2023]
Abstract
Electrochemically active metals offer advanced functionalities with respect to the well-established gold electrode arrangements in various electronic transport experiments on atomic scale objects. Such functionalities can arise from stronger interactions with the leads which provide better coupling to specific molecules and may also facilitate metallic filament formation in atomic switches. However, the higher reactivity of the electrode metal also imposes challenges in the fabrication and reliability of nanometer scale platforms, limiting the number of reported applications. Here we present a high-yield lithographic fabrication procedure suitable to extend the experimental toolkit with mechanically controllable break junctions of oxygen sensitive metallic electrodes. We fabricate and characterize silver break junctions exhibiting single-atomic conductance and superior mechanical and electrical stability at room temperature. As a proof-of-principle application, we demonstrate resistive switching between metastable few-atom configurations at finite voltage bias.
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Affiliation(s)
- Anna Nyáry
- Department of Physics, Budapest University of Technology and Economics Budafoki út 8 1111 Budapest Hungary
- MTA-BME Condensed Matter Research Group Budafoki út 8 1111 Budapest Hungary
| | - Agnes Gubicza
- Department of Physics, Budapest University of Technology and Economics Budafoki út 8 1111 Budapest Hungary
- Empa, Swiss Federal Laboratories for Materials Science and Technology, Transport at Nanoscale Interfaces Laboratory Überlandstrasse 129 CH-8600 Dübendorf Switzerland
| | - Jan Overbeck
- Empa, Swiss Federal Laboratories for Materials Science and Technology, Transport at Nanoscale Interfaces Laboratory Überlandstrasse 129 CH-8600 Dübendorf Switzerland
- Swiss Nanoscience Institute, University of Basel Klingelbergstrasse 82 CH-4056 Basel Switzerland
| | - László Pósa
- Department of Physics, Budapest University of Technology and Economics Budafoki út 8 1111 Budapest Hungary
- Institute of Technical Physics and Materials Science, Centre for Energy Research Konkoly-Thege M. út 29-33 1121 Budapest Hungary
| | - Péter Makk
- Department of Physics, Budapest University of Technology and Economics Budafoki út 8 1111 Budapest Hungary
- Department of Physics, University of Basel Klingelbergstrasse 82 CH-4056 Basel Switzerland
| | - Michel Calame
- Empa, Swiss Federal Laboratories for Materials Science and Technology, Transport at Nanoscale Interfaces Laboratory Überlandstrasse 129 CH-8600 Dübendorf Switzerland
- Swiss Nanoscience Institute, University of Basel Klingelbergstrasse 82 CH-4056 Basel Switzerland
- Department of Physics, University of Basel Klingelbergstrasse 82 CH-4056 Basel Switzerland
| | - András Halbritter
- Department of Physics, Budapest University of Technology and Economics Budafoki út 8 1111 Budapest Hungary
- MTA-BME Condensed Matter Research Group Budafoki út 8 1111 Budapest Hungary
| | - Miklós Csontos
- Department of Physics, Budapest University of Technology and Economics Budafoki út 8 1111 Budapest Hungary
- Empa, Swiss Federal Laboratories for Materials Science and Technology, Transport at Nanoscale Interfaces Laboratory Überlandstrasse 129 CH-8600 Dübendorf Switzerland
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10
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Wagner G, Nguyen DX, Simon SH. Transport in Bilayer Graphene near Charge Neutrality: Which Scattering Mechanisms Are Important? PHYSICAL REVIEW LETTERS 2020; 124:026601. [PMID: 32004029 DOI: 10.1103/physrevlett.124.026601] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Indexed: 06/10/2023]
Abstract
Using the semiclassical quantum Boltzmann equation (QBE), we numerically calculate the dc transport properties of bilayer graphene near charge neutrality. We find, in contrast to prior discussions, that phonon scattering is crucial even at temperatures below 40 K. Nonetheless, electron-electron scattering still dominates over phonon collisions allowing a hydrodynamic approach. We introduce a simple two-fluid hydrodynamic model of electrons and holes interacting via Coulomb drag and compare our results to the full QBE calculation. We show that the two-fluid model produces quantitatively accurate results for conductivity, thermopower, and thermal conductivity.
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Affiliation(s)
- Glenn Wagner
- Rudolf Peierls Centre for Theoretical Physics, Parks Road, Oxford OX1 3PU, United Kingdom
| | - Dung X Nguyen
- Rudolf Peierls Centre for Theoretical Physics, Parks Road, Oxford OX1 3PU, United Kingdom
| | - Steven H Simon
- Rudolf Peierls Centre for Theoretical Physics, Parks Road, Oxford OX1 3PU, United Kingdom
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11
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Cea T, Walet NR, Guinea F. Twists and the Electronic Structure of Graphitic Materials. NANO LETTERS 2019; 19:8683-8689. [PMID: 31743649 DOI: 10.1021/acs.nanolett.9b03335] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
We analyze the effect of twists on the electronic structure of configurations of infinite stacks of graphene layers. We focus on three different cases: an infinite stack where each layer is rotated with respect to the previous one by a fixed angle, two pieces of semi-infinite graphite rotated with respect to each other, and finally a single layer of graphene rotated with respect to a graphite surface. In all three cases, we find a rich structure, with sharp resonances and flat bands for small twist angles. The method used can be easily generalized to more complex arrangements and stacking sequences.
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Affiliation(s)
- Tommaso Cea
- Imdea Nanoscience , Faraday 9 , 28015 Madrid , Spain
| | - Niels R Walet
- School of Physics and Astronomy , University of Manchester , Manchester , M13 9PY , U.K
| | - Francisco Guinea
- Imdea Nanoscience , Faraday 9 , 28015 Madrid , Spain
- School of Physics and Astronomy , University of Manchester , Manchester , M13 9PY , U.K
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12
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García-Ruiz A, Slizovskiy S, Mucha-Kruczyński M, Fal’ko VI. Spectroscopic Signatures of Electronic Excitations in Raman Scattering in Thin Films of Rhombohedral Graphite. NANO LETTERS 2019; 19:6152-6156. [PMID: 31361497 PMCID: PMC7007278 DOI: 10.1021/acs.nanolett.9b02196] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Revised: 07/22/2019] [Indexed: 06/10/2023]
Abstract
Rhombohedral graphite features peculiar electronic properties, including persistence of low-energy surface bands of a topological nature. Here, we study the contribution of electron-hole excitations toward inelastic light scattering in thin films of rhombohedral graphite. We show that, in contrast to the featureless electron-hole contribution toward Raman spectrum of graphitic films with Bernal stacking, the inelastic light scattering accompanied by electron-hole excitations in crystals with rhombohedral stacking produces distinct features in the Raman signal which can be used both to identify the stacking and to determine the number of layers in the film.
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Affiliation(s)
- Aitor García-Ruiz
- Department
of Physics, University of Bath, Claverton Down, Bath BA2 3FL, United Kingdom
| | - Sergey Slizovskiy
- National
Graphene Institute, University of Manchester, Booth Street E, Manchester M13 9PL, United
Kingdom
- Department
of Physics and Astronomy, University of
Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
| | - Marcin Mucha-Kruczyński
- Department
of Physics, University of Bath, Claverton Down, Bath BA2 3FL, United Kingdom
- Centre
for Nanoscience and Nanotechnology, University
of Bath, Claverton Down, Bath BA2 3FL, United Kingdom
| | - Vladimir I. Fal’ko
- National
Graphene Institute, University of Manchester, Booth Street E, Manchester M13 9PL, United
Kingdom
- Department
of Physics and Astronomy, University of
Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
- Henry
Royce Institute, Manchester M13 9PL, United Kingdom
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