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Bahamon DA, Gómez-Santos G, Efetov DK, Stauber T. Chirality Probe of Twisted Bilayer Graphene in the Linear Transport Regime. NANO LETTERS 2024; 24:4478-4484. [PMID: 38584591 PMCID: PMC11036400 DOI: 10.1021/acs.nanolett.4c00371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2024] [Revised: 03/27/2024] [Accepted: 03/27/2024] [Indexed: 04/09/2024]
Abstract
We propose minimal transport experiments in the coherent regime that can probe the chirality of twisted moiré structures. We show that only with a third contact and in the presence of an in-plane magnetic field (or another time-reversal symmetry breaking effect) a chiral system may display nonreciprocal transport in the linear regime. We then propose to use the third lead as a voltage probe and show that opposite enantiomers give rise to different voltage drops on the third lead. Additionally, in the scenario of layer-discriminating contacts, the third lead can serve as a current probe capable of detecting different handedness even in the absence of a magnetic field. In a complementary configuration, applying opposite voltages on the two layers of the third lead gives rise to a chiral (super)current in the absence of a source-drain voltage whose direction is determined by its chirality.
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Affiliation(s)
- Dario A. Bahamon
- School of Engineering, Mackenzie Presbyterian University, São Paulo 01302-907, Brazil
- MackGraphe
Graphene and Nanomaterials Research Institute, Mackenzie Presbyterian University, São Paulo 01302-907, Brazil
- Departamento
de Teoría y Simulación de Materiales, Instituto de Ciencias de Materiales de Madrid, CSIC, E-28049 Madrid, Spain
| | - Guillermo Gómez-Santos
- Departamento
de Física de la Materia Condensada, Instituto Nicolás
Cabrera and Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, E-28049 Madrid, Spain
| | - Dmitri K. Efetov
- Fakultät
für Physik, Ludwig-Maximilians-Universität, Schellingstrasse 4, D-80799 München, Germany
- Munich Center
for Quantum Science and Technology (MCQST), Schellingstrasse 4, D-80799 München, Germany
| | - Tobias Stauber
- Departamento
de Teoría y Simulación de Materiales, Instituto de Ciencias de Materiales de Madrid, CSIC, E-28049 Madrid, Spain
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Kuang X, Pantaleón Peralta PA, Angel Silva-Guillén J, Yuan S, Guinea F, Zhan Z. Optical properties and plasmons in moiré structures. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2024; 36:173001. [PMID: 38232397 DOI: 10.1088/1361-648x/ad1f8c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Accepted: 01/17/2024] [Indexed: 01/19/2024]
Abstract
The discoveries of numerous exciting phenomena in twisted bilayer graphene (TBG) are stimulating significant investigations on moiré structures that possess a tunable moiré potential. Optical response can provide insights into the electronic structures and transport phenomena of non-twisted and twisted moiré structures. In this article, we review both experimental and theoretical studies of optical properties such as optical conductivity, dielectric function, non-linear optical response, and plasmons in moiré structures composed of graphene, hexagonal boron nitride (hBN), and/or transition metal dichalcogenides. Firstly, a comprehensive introduction to the widely employed methodology on optical properties is presented. After, moiré potential induced optical conductivity and plasmons in non-twisted structures are reviewed, such as single layer graphene-hBN, bilayer graphene-hBN and graphene-metal moiré heterostructures. Next, recent investigations of twist-angle dependent optical response and plasmons are addressed in twisted moiré structures. Additionally, we discuss how optical properties and plasmons could contribute to the understanding of the many-body effects and superconductivity observed in moiré structures.
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Affiliation(s)
- Xueheng Kuang
- Yangtze Delta Industrial Innovation Center of Quantum Science and Technology, Suzhou 215000, People's Republic of China
| | | | - Jose Angel Silva-Guillén
- Instituto Madrileño de Estudios Avanzados, IMDEA Nanociencia, Calle Faraday 9, 28049 Madrid, Spain
| | - Shengjun Yuan
- Key Laboratory of Artificial Micro- and Nano-structures of the Ministry of Education and School of Physics and Technology, Wuhan University, Wuhan 430072, People's Republic of China
- Wuhan Institute of Quantum Technology, Wuhan 430206, People's Republic of China
| | - Francisco Guinea
- Instituto Madrileño de Estudios Avanzados, IMDEA Nanociencia, Calle Faraday 9, 28049 Madrid, Spain
- Donostia International Physics Center, Paseo Manuel de Lardizábal 4, 20018 San Sebastián, Spain
| | - Zhen Zhan
- Instituto Madrileño de Estudios Avanzados, IMDEA Nanociencia, Calle Faraday 9, 28049 Madrid, Spain
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Wang H, Kumar A, Dai S, Lin X, Jacob Z, Oh SH, Menon V, Narimanov E, Kim YD, Wang JP, Avouris P, Martin Moreno L, Caldwell J, Low T. Planar hyperbolic polaritons in 2D van der Waals materials. Nat Commun 2024; 15:69. [PMID: 38167681 PMCID: PMC10761702 DOI: 10.1038/s41467-023-43992-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2023] [Accepted: 11/27/2023] [Indexed: 01/05/2024] Open
Abstract
Anisotropic planar polaritons - hybrid electromagnetic modes mediated by phonons, plasmons, or excitons - in biaxial two-dimensional (2D) van der Waals crystals have attracted significant attention due to their fundamental physics and potential nanophotonic applications. In this Perspective, we review the properties of planar hyperbolic polaritons and the variety of methods that can be used to experimentally tune them. We argue that such natural, planar hyperbolic media should be fairly common in biaxial and uniaxial 2D and 1D van der Waals crystals, and identify the untapped opportunities they could enable for functional (i.e. ferromagnetic, ferroelectric, and piezoelectric) polaritons. Lastly, we provide our perspectives on the technological applications of such planar hyperbolic polaritons.
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Affiliation(s)
- Hongwei Wang
- Department of Electrical and Computer Engineering, University of Minnesota, Minneapolis, MN, 55455, USA
- Institute of High Pressure Physics, School of Physical Science and Technology, Ningbo University, 315211, Ningbo, China
| | - Anshuman Kumar
- Laboratory of Optics of Quantum Materials, Department of Physics, IIT Bombay, Mumbai, Maharashtra, 400076, India
| | - Siyuan Dai
- Department of Mechanical Engineering, Materials Research and Education Center, Auburn University, Auburn, AL, 36849, USA
| | - Xiao Lin
- Interdisciplinary Center for Quantum Information, State Key Laboratory of Extreme Photonics and Instrumentation, ZJU-Hangzhou Global Science and Technology Innovation Center, College of Information Science and Electronic Engineering, Zhejiang University, 310027, Hangzhou, China
| | - Zubin Jacob
- Birck Nanotechnology Center, School of Electrical and Computer Engineering, Purdue University, West Lafayette, IN, 47907, USA
| | - Sang-Hyun Oh
- Department of Electrical and Computer Engineering, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Vinod Menon
- Department of Physics, City College and Graduate Center, City University of New York, New York, NY, 10031, USA
| | - Evgenii Narimanov
- Birck Nanotechnology Center, School of Electrical and Computer Engineering, Purdue University, West Lafayette, IN, 47907, USA
| | - Young Duck Kim
- Department of Physics and Department of Information Display, Kyung Hee University, Seoul, 02447, Republic of Korea
| | - Jian-Ping Wang
- Department of Electrical and Computer Engineering, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Phaedon Avouris
- Department of Electrical and Computer Engineering, University of Minnesota, Minneapolis, MN, 55455, USA
- IBM T. J. Watson Research Center, Yorktown Heights, NY, 10598, USA
| | - Luis Martin Moreno
- Instituto de Nanociencia y Materiales de Aragon (INMA), CSIC-Universidad de Zaragoza, Zaragoza, 50009, Spain
- Departamento de Fisica de la Materia Condensada, Universidad de Zaragoza, Zaragoza, 50009, Spain
| | - Joshua Caldwell
- Department of Mechanical Engineering, Vanderbilt University, Nashville, TN, 37235, USA
| | - Tony Low
- Department of Electrical and Computer Engineering, University of Minnesota, Minneapolis, MN, 55455, USA.
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4
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Halterman K. Controlled light energy and perfect absorption in twisted bilayer graphene. OPTICS EXPRESS 2023; 31:42901-42925. [PMID: 38178398 DOI: 10.1364/oe.509346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Accepted: 11/10/2023] [Indexed: 01/06/2024]
Abstract
We theoretically study the components of the dynamical optical conductivity tensor and associated finite-frequency dielectric response of bilayer graphene (BLG), where one graphene layer can slide in-plane or commensurably twist on top of the other. Our results reveal that even slight deviations from the conventional AA, AB, or AC stacking orders yield a finite transverse conductivity. Upon calculating the optical conductivity of the BLG at any arbitrary interlayer displacement, Δ, and chemical potential, µ, it is utilized for a layered device with an epsilon-near-zero (ENZ) insert and metallic back plate. We find that both Δ and µ can effectively control the polarization, energy flow direction, and absorptivity of linearly polarized incident light. By appropriately tailoring Δ and µ, near-perfect absorption and tunable dissipation can be accessible through particular angles of incidence and a broad range of ENZ layer thicknesses. Our findings can be applied to the design of programmable optoelectronics devices.
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Han Z, Wang F, Sun J, Wang X, Tang Z. Recent Advances in Ultrathin Chiral Metasurfaces by Twisted Stacking. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2206141. [PMID: 36284479 DOI: 10.1002/adma.202206141] [Citation(s) in RCA: 20] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Revised: 09/22/2022] [Indexed: 06/16/2023]
Abstract
Artificial chiral nanostructures have been subjected to extensive research for their unique chiroptical activities. Planarized chiral films of ultrathin thicknesses are in particular demand for easy on-chip integration and improved energy efficiency as polarization-sensitive metadevices. Recently, controlled twisted stacking of two or more layers of nanomaterials, such as 2D van der Waals materials, ultrathin films, or traditional metasurfaces, at an angle has emerged as a general strategy to introduce optical chirality into achiral solid-state systems. This method endows new degrees of freedom, e.g., the interlayer twist angle, to flexibly engineer and tune the chiroptical responses without having to change the material or the design, thus greatly facilitating the development of multifunctional metamaterials. In this review, recent exciting progress in planar chiral metasurfaces are summarized and discussed from the viewpoints of building blocks, fabrication methods, as well as circular dichroism and modulation thereof in twisted stacked nanostructures. The review further highlights the ever-growing portfolio of applications of these chiral metasurfaces, including polarization conversion, information encryption, chiral sensing, and as an engineering platform for hybrid metadevices. Finally, forward-looking prospects are provided.
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Affiliation(s)
- Zexiang Han
- CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology, Beijing, 100190, P. R. China
| | - Fei Wang
- CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology, Beijing, 100190, P. R. China
| | - Juehan Sun
- CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology, Beijing, 100190, P. R. China
| | - Xiaoli Wang
- CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology, Beijing, 100190, P. R. China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
| | - Zhiyong Tang
- CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology, Beijing, 100190, P. R. China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
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6
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Observation of chiral and slow plasmons in twisted bilayer graphene. Nature 2022; 605:63-68. [PMID: 35508778 DOI: 10.1038/s41586-022-04520-8] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Accepted: 02/04/2022] [Indexed: 11/08/2022]
Abstract
Moiré superlattices have led to observations of exotic emergent electronic properties such as superconductivity and strong correlated states in small-rotation-angle twisted bilayer graphene (tBLG)1,2. Recently, these findings have inspired the search for new properties in moiré plasmons. Although plasmon propagation in the tBLG basal plane has been studied by near-field nano-imaging techniques3-7, the general electromagnetic character and properties of these plasmons remain elusive. Here we report the direct observation of two new plasmon modes in macroscopic tBLG with a highly ordered moiré superlattice. Using spiral structured nanoribbons of tBLG, we identify signatures of chiral plasmons that arise owing to the uncompensated Berry flux of the electron gas under optical pumping. The salient features of these chiral plasmons are shown through their dependence on optical pumping intensity and electron fillings, in conjunction with distinct resonance splitting and Faraday rotation coinciding with the spectral window of maximal Berry flux. Moreover, we also identify a slow plasmonic mode around 0.4 electronvolts, which stems from the interband transitions between the nested subbands in lattice-relaxed AB-stacked domains. This mode may open up opportunities for strong light-matter interactions within the highly sought after mid-wave infrared spectral window8. Our results unveil the new electromagnetic dynamics of small-angle tBLG and exemplify it as a unique quantum optical platform.
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7
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Interface nano-optics with van der Waals polaritons. Nature 2021; 597:187-195. [PMID: 34497390 DOI: 10.1038/s41586-021-03581-5] [Citation(s) in RCA: 73] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2020] [Accepted: 04/23/2021] [Indexed: 01/27/2023]
Abstract
Polaritons are hybrid excitations of matter and photons. In recent years, polaritons in van der Waals nanomaterials-known as van der Waals polaritons-have shown great promise to guide the flow of light at the nanoscale over spectral regions ranging from the visible to the terahertz. A vibrant research field based on manipulating strong light-matter interactions in the form of polaritons, supported by these atomically thin van der Waals nanomaterials, is emerging for advanced nanophotonic and opto-electronic applications. Here we provide an overview of the state of the art of exploiting interface optics-such as refractive optics, meta-optics and moiré engineering-for the control of van der Waals polaritons. This enhanced control over van der Waals polaritons at the nanoscale has not only unveiled many new phenomena, but has also inspired valuable applications-including new avenues for nano-imaging, sensing, on-chip optical circuitry, and potentially many others in the years to come.
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8
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Zuber JW, Zhang C. Twist dependent magneto-optical response in twisted bilayer graphene. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2021; 33:445501. [PMID: 34375960 DOI: 10.1088/1361-648x/ac1c30] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 08/10/2021] [Indexed: 06/13/2023]
Abstract
By employing a linearised Boltzmann equation, we calculate the magneto-optical properties of twisted bilayer graphene using non-magnetic wave functions. Both transverse and longitudinal responses are calculated up to the second order in applied magnetic field with their twist angle and Fermi level dependence examined. We find that increasing the twist angle increases the transverse metallic response so long as the Fermi level remains below the upper conduction band. Interlayer transitions provide an appreciable enhancement when the Fermi level traverses the gap between the two conduction bands. Interlayer transitions are also responsible for a nonzero anomalous Hall conductivity in this model. As the Fermi level moves towards zero, the longitudinal response begins to dominate and a highly anisotropic negative magneto-resistance is observed.
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Affiliation(s)
- J W Zuber
- School of Physics and Institute for Superconducting and Electronic Materials, University of Wollongong, New South Wales 2522, Australia
| | - C Zhang
- School of Physics and Institute for Superconducting and Electronic Materials, University of Wollongong, New South Wales 2522, Australia
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9
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Nanophotonic biosensors harnessing van der Waals materials. Nat Commun 2021; 12:3824. [PMID: 34158483 PMCID: PMC8219843 DOI: 10.1038/s41467-021-23564-4] [Citation(s) in RCA: 52] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Accepted: 04/16/2021] [Indexed: 02/07/2023] Open
Abstract
Low-dimensional van der Waals (vdW) materials can harness tightly confined polaritonic waves to deliver unique advantages for nanophotonic biosensing. The reduced dimensionality of vdW materials, as in the case of two-dimensional graphene, can greatly enhance plasmonic field confinement, boosting sensitivity and efficiency compared to conventional nanophotonic devices that rely on surface plasmon resonance in metallic films. Furthermore, the reduction of dielectric screening in vdW materials enables electrostatic tunability of different polariton modes, including plasmons, excitons, and phonons. One-dimensional vdW materials, particularly single-walled carbon nanotubes, possess unique form factors with confined excitons to enable single-molecule detection as well as in vivo biosensing. We discuss basic sensing principles based on vdW materials, followed by technological challenges such as surface chemistry, integration, and toxicity. Finally, we highlight progress in harnessing vdW materials to demonstrate new sensing functionalities that are difficult to perform with conventional metal/dielectric sensors. This review presents an overview of scenarios where van der Waals (vdW) materials provide unique advantages for nanophotonic biosensing applications. The authors discuss basic sensing principles based on vdW materials, advantages of the reduced dimensionality as well as technological challenges.
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Zhao R, Li J, Zhang Q, Liu X, Zhang Y. Behavior of SPPs in chiral-graphene-chiral structure. OPTICS LETTERS 2021; 46:1975-1978. [PMID: 33857120 DOI: 10.1364/ol.422998] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Accepted: 03/22/2021] [Indexed: 06/12/2023]
Abstract
In this Letter, considering the chiral-graphene-chiral structure, we investigate the more universal dispersion relation covering the achiral cases, the effect of the chirality of a medium, and the chemical potential of graphene on the behavior of graphene surface plasmon polaritons (GSPPs) and transverse spin density, which is key to understanding the lateral optical force. This research is dedicated to looking for a regulating mechanism based on chirality and graphene to apply in devices of information processing and biosensor for identifying molecular chirality. We found the averaging effect of chirality in both sides of graphene in tuning the behavior of GSPPs. We believe this work can make contributions to enrich SPP theory and benefit the development of novel detection techniques for chiral molecules based on graphene.
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Li S, Wang H, Wang J, Chen H, Shao L. Control of light-valley interactions in 2D transition metal dichalcogenides with nanophotonic structures. NANOSCALE 2021; 13:6357-6372. [PMID: 33885520 DOI: 10.1039/d0nr08000d] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Electronic valley in two-dimensional transition-metal dichalcogenides (2D TMDCs) offers a new degree of freedom for information storage and processing. The valley pseudospin can be optically encoded by photons with specific helicity, enabling the construction of electronic information devices with both high performance and low power consumption. Robust detection, manipulation and transport of the valley pseudospins at room temperature are still challenging because of the short lifetime of valley-polarized carriers and excitons. Integrating 2D TMDCs with nanophotonic objects such as plasmonic nanostructures provides a competitive solution to address the challenge. The research in this field is of practical interest and can also present rich physics of light-matter interactions. In this minireview, recent progress on using nanophotonic strategies to enhance the valley polarization degree, especially at room temperature, is highlighted. Open questions, major challenges, and interesting future developments in manipulating the valley information in 2D semiconductors with the help of nanophotonic structures will also be discussed.
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Affiliation(s)
- Shasha Li
- Beijing Computational Science Research Center, Beijing 100193, China.
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Stauber T, Low T, Gómez-Santos G. Plasmon-Enhanced Near-Field Chirality in Twisted van der Waals Heterostructures. NANO LETTERS 2020; 20:8711-8718. [PMID: 33237775 DOI: 10.1021/acs.nanolett.0c03519] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
It is shown that chiral plasmons, characterized by a longitudinal magnetic moment accompanying the longitudinal charge plasmon, lead to electromagnetic near-fields that are also chiral. For twisted bilayer graphene, we estimate that the near-field chirality of screened plasmons can be several orders of magnitude larger than that of the related circularly polarized light. The chirality also manifests itself in a deflection angle that is formed between the direction of the plasmon propagation and its Poynting vector. Twisted van der Waals heterostructures might thus provide a novel platform to promote enantiomer-selective physio-chemical processes in chiral molecules without the application of a magnetic field or external nanopatterning that break time-reversal, mirror plane, or inversion symmetry, respectively.
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Affiliation(s)
- Tobias Stauber
- Departamento de Teoría y Simulación de Materiales, Instituto de Ciencia de Materiales de Madrid, CSIC, 28049 Madrid, Spain
| | - Tony Low
- Department of Electrical and Computer Engineering, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Guillermo Gómez-Santos
- Departamento de Física de la Materia Condensada, INC and IFIMAC, Universidad Autónoma de Madrid, E-28049 Madrid, Spain
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