1
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Tabataba-Vakili F, Krelle L, Husel L, Nguyen HPG, Li Z, Bilgin I, Watanabe K, Taniguchi T, Högele A. Metasurface of Strongly Coupled Excitons and Nanoplasmonic Arrays. NANO LETTERS 2024; 24:10090-10097. [PMID: 39106977 PMCID: PMC11342386 DOI: 10.1021/acs.nanolett.4c02043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2024] [Revised: 07/16/2024] [Accepted: 07/17/2024] [Indexed: 08/09/2024]
Abstract
Metasurfaces allow light to be manipulated at the nanoscale. Integrating metasurfaces with transition metal dichalcogenide monolayers provides additional functionality to ultrathin optics, including tunable optical properties with enhanced light-matter interactions. In this work, we demonstrate the realization of a polaritonic metasurface utilizing the sizable light-matter coupling of excitons in monolayer WSe2 and the collective lattice resonances of nanoplasmonic gold arrays. We developed a novel fabrication method to integrate gold nanodisk arrays in hexagonal boron nitride and thus simultaneously ensure spectrally narrow exciton transitions and their immediate proximity to the near-field of array surface lattice resonances. In the regime of strong light-matter coupling, the resulting van der Waals metasurface exhibits all key characteristics of lattice polaritons, with a directional and linearly polarized far-field emission profile dictated by the underlying nanoplasmonic lattice. Our work can be straightforwardly adapted to other lattice geometries, establishing structured van der Waals metasurfaces as means to engineer polaritonic lattices.
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Affiliation(s)
- Farsane Tabataba-Vakili
- Fakultät
für Physik, Munich Quantum Center, and Center for NanoScience
(CeNS), Ludwig-Maximilians-Universität
München, Geschwister-Scholl-Platz 1, 80539 München, Germany
- Munich
Center for Quantum Science and Technology (MCQST), Schellingtraße 4, 80799 München, Germany
| | - Lukas Krelle
- Fakultät
für Physik, Munich Quantum Center, and Center for NanoScience
(CeNS), Ludwig-Maximilians-Universität
München, Geschwister-Scholl-Platz 1, 80539 München, Germany
| | - Lukas Husel
- Fakultät
für Physik, Munich Quantum Center, and Center for NanoScience
(CeNS), Ludwig-Maximilians-Universität
München, Geschwister-Scholl-Platz 1, 80539 München, Germany
| | - Huy P. G. Nguyen
- Fakultät
für Physik, Munich Quantum Center, and Center for NanoScience
(CeNS), Ludwig-Maximilians-Universität
München, Geschwister-Scholl-Platz 1, 80539 München, Germany
| | - Zhijie Li
- Fakultät
für Physik, Munich Quantum Center, and Center for NanoScience
(CeNS), Ludwig-Maximilians-Universität
München, Geschwister-Scholl-Platz 1, 80539 München, Germany
| | - Ismail Bilgin
- Fakultät
für Physik, Munich Quantum Center, and Center for NanoScience
(CeNS), Ludwig-Maximilians-Universität
München, Geschwister-Scholl-Platz 1, 80539 München, Germany
| | - Kenji Watanabe
- Research
Center for Functional Materials, National
Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Takashi Taniguchi
- International
Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Alexander Högele
- Fakultät
für Physik, Munich Quantum Center, and Center for NanoScience
(CeNS), Ludwig-Maximilians-Universität
München, Geschwister-Scholl-Platz 1, 80539 München, Germany
- Munich
Center for Quantum Science and Technology (MCQST), Schellingtraße 4, 80799 München, Germany
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2
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Singh S, Kim KH, Jo K, Musavigharavi P, Kim B, Zheng J, Trainor N, Chen C, Redwing JM, Stach EA, Olsson RH, Jariwala D. Nonvolatile Control of Valley Polarized Emission in 2D WSe 2-AlScN Heterostructures. ACS NANO 2024; 18:17958-17968. [PMID: 38918951 DOI: 10.1021/acsnano.4c04684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/27/2024]
Abstract
Achieving robust and electrically controlled valley polarization in monolayer transition metal dichalcogenides (ML-TMDs) is a frontier challenge for realistic valleytronic applications. Theoretical investigations show that the integration of 2D materials with ferroelectrics is a promising strategy; however, an experimental demonstration has remained elusive. Here, we fabricate ferroelectric field-effect transistors using a ML-WSe2 channel and an Al0.68Sc0.32N (AlScN) ferroelectric dielectric and experimentally demonstrate efficient tuning as well as non-volatile control of valley polarization. We measure a large array of transistors and obtain a maximum valley polarization of ∼27% at 80 K with stable retention up to 5400 s. The enhancement in the valley polarization is ascribed to the efficient exciton-to-trion (X-T) conversion and its coupling with an out-of-plane electric field, viz., the quantum-confined Stark effect. This changes the valley depolarization pathway from strong exchange interactions to slow spin-flip intervalley scattering. Our research demonstrates a promising approach for achieving non-volatile control over valley polarization for practical valleytronic device applications.
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Affiliation(s)
- Simrjit Singh
- Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
- Department of Applied Physics and Science Education, Eindhoven University of Technology, Eindhoven 5600 MB, The Netherlands
| | - Kwan-Ho Kim
- Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Kiyoung Jo
- Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Pariasadat Musavigharavi
- Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
- Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
- Department of Materials Science and Engineering, University of Central Florida, Orlando, Florida 32816, United States
| | - Bumho Kim
- Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Jeffrey Zheng
- Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Nicholas Trainor
- Department of Materials Science and Engineering, Pennsylvania State University, University Park, Pennsylvania 16801, United States
| | - Chen Chen
- 2D Crystal Consortium Materials Innovation Platform, Materials Research Institute, Pennsylvania State University, University Park, Pennsylvania 16801, United States
| | - Joan M Redwing
- Department of Materials Science and Engineering, Pennsylvania State University, University Park, Pennsylvania 16801, United States
- 2D Crystal Consortium Materials Innovation Platform, Materials Research Institute, Pennsylvania State University, University Park, Pennsylvania 16801, United States
| | - Eric A Stach
- Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Roy H Olsson
- Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Deep Jariwala
- Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
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3
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Dai D, Fu B, Yang J, Yang L, Yan S, Chen X, Li H, Zuo Z, Wang C, Jin K, Gong Q, Xu X. Twist angle-dependent valley polarization switching in heterostructures. SCIENCE ADVANCES 2024; 10:eado1281. [PMID: 38748802 PMCID: PMC11095485 DOI: 10.1126/sciadv.ado1281] [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: 01/17/2024] [Accepted: 04/12/2024] [Indexed: 05/19/2024]
Abstract
The twist engineering of moiré superlattice in van der Waals heterostructures of transition metal dichalcogenides can manipulate valley physics of interlayer excitons (IXs), paving the way for next-generation valleytronic devices. However, the twist angle-dependent control of excitonic potential on valley polarization is not investigated so far in electrically controlled heterostructures and the physical mechanism underneath needs to be explored. Here, we demonstrate the dependence of both polarization switching and degree of valley polarization on the moiré period. We also find the mechanisms to reveal the modulation of twist angle on the exciton potential and the electron-hole exchange interaction, which elucidate the experimentally observed twist angle-dependent valley polarization of IXs. Furthermore, we realize the valley-addressable devices based on polarization switch. Our work demonstrates the manipulation of the valley polarization of IXs by tunning twist angle in electrically controlled heterostructures, which opens an avenue for electrically controlling the valley degrees of freedom in twistronic devices.
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Affiliation(s)
- Danjie Dai
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- CAS Center for Excellence in Topological Quantum Computation and School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Bowen Fu
- State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics, School of Physics, Peking University, Beijing 100871, China
| | - Jingnan Yang
- State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics, School of Physics, Peking University, Beijing 100871, China
| | - Longlong Yang
- State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics, School of Physics, Peking University, Beijing 100871, China
| | - Sai Yan
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- CAS Center for Excellence in Topological Quantum Computation and School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiqing Chen
- State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics, School of Physics, Peking University, Beijing 100871, China
| | - Hancong Li
- State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics, School of Physics, Peking University, Beijing 100871, China
| | - Zhanchun Zuo
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- CAS Center for Excellence in Topological Quantum Computation and School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Can Wang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- CAS Center for Excellence in Topological Quantum Computation and School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
| | - Kuijuan Jin
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- CAS Center for Excellence in Topological Quantum Computation and School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
| | - Qihuang Gong
- State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics, School of Physics, Peking University, Beijing 100871, China
- Peking University Yangtze Delta Institute of Optoelectronics, Nantong, Jiangsu 226010, China
| | - Xiulai Xu
- State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics, School of Physics, Peking University, Beijing 100871, China
- Peking University Yangtze Delta Institute of Optoelectronics, Nantong, Jiangsu 226010, China
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4
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Jo K, Stevens CE, Choi B, El-Khoury PZ, Hendrickson JR, Jariwala D. Core/Shell-Like Localized Emission at Atomically Thin Semiconductor-Au Interface. NANO LETTERS 2024. [PMID: 38593418 DOI: 10.1021/acs.nanolett.3c03790] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/11/2024]
Abstract
Localized emission in atomically thin semiconductors has sparked significant interest as single-photon sources. Despite comprehensive studies into the correlation between localized strain and exciton emission, the impacts of charge transfer on nanobubble emission remains elusive. Here, we report the observation of core/shell-like localized emission from monolayer WSe2 nanobubbles at room temperature through near-field studies. By altering the electronic junction between monolayer WSe2 and the Au substrate, one can effectively adjust the semiconductor to metal junction from a Schottky to an Ohmic junction. Through concurrent analysis of topography, potential, tip-enhanced photoluminescence, and a piezo response force microscope, we attribute the core/shell-like emissions to strong piezoelectric potential aided by induced polarity at the WSe2-Au Schottky interface which results in spatial confinement of the excitons. Our findings present a new approach for manipulating charge confinement and engineering localized emission within atomically thin semiconductor nanobubbles. These insights hold implications for advancing the nano and quantum photonics with low-dimensional semiconductors.
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Affiliation(s)
- Kiyoung Jo
- Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
- Physical Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Christopher E Stevens
- KBR Inc., Beavercreek, Ohio 45431, United States
- Sensors Directorate, Air Force Research Laboratory, Wright-Patterson AFB Ohio 45433, United States
| | - Bongjun Choi
- Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Patrick Z El-Khoury
- Physical Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | - Joshua R Hendrickson
- Sensors Directorate, Air Force Research Laboratory, Wright-Patterson AFB Ohio 45433, United States
| | - Deep Jariwala
- Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
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5
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Perea-Causin R, Brem S, Schmidt O, Malic E. Trion Photoluminescence and Trion Stability in Atomically Thin Semiconductors. PHYSICAL REVIEW LETTERS 2024; 132:036903. [PMID: 38307073 DOI: 10.1103/physrevlett.132.036903] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Accepted: 12/04/2023] [Indexed: 02/04/2024]
Abstract
The optical response of doped monolayer semiconductors is governed by trions, i.e. photoexcited electron-hole pairs bound to doping charges. While their photoluminescence (PL) signatures have been identified in experiments, a microscopic model consistently capturing bright and dark trion peaks is still lacking. In this work, we derive a generalized trion PL formula on a quantum-mechanical footing, considering direct and phonon-assisted recombination mechanisms. We show the trion energy landscape in WSe_{2} by solving the trion Schrödinger equation. We reveal that the mass imbalance between equal charges results in less stable trions exhibiting a small binding energy and, interestingly, a large energetic offset from exciton peaks in PL spectra. Furthermore, we compute the temperature-dependent PL spectra for n- and p-doped monolayers and predict yet unobserved signatures originating from trions with an electron at the Λ point. Our work presents an important step toward a microscopic understanding of the internal structure of trions determining their stability and optical fingerprint.
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Affiliation(s)
- Raul Perea-Causin
- Department of Physics, Chalmers University of Technology, 412 96 Gothenburg, Sweden
| | - Samuel Brem
- Department of Physics, Philipps-Universität Marburg, 35032 Marburg, Germany
| | - Ole Schmidt
- Department of Physics, Philipps-Universität Marburg, 35032 Marburg, Germany
| | - Ermin Malic
- Department of Physics, Philipps-Universität Marburg, 35032 Marburg, Germany
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6
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Chen H, Wang Q, Feng X, Wu W, Zhang L. Phonon Chirality Manipulation Mechanism in Transition-Metal Dichalcogenide Interlayer-Sliding Ferroelectrics. NANO LETTERS 2023. [PMID: 37976102 DOI: 10.1021/acs.nanolett.3c03787] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2023]
Abstract
As an ideal platform, both the theoretical prediction and first experimental verification of chiral phonons are based on transition-metal dichalcogenide materials. The manipulation of phonon chirality in these materials will have a profound effect on the study of chiral phonons. In this work, we utilize the sliding ferroelectric effect to realize the phonon chirality manipulation mechanism in transition-metal dichalcogenide materials. Based on first-principles calculations, we find the different manipulation effects of interlayer sliding on the phonon chirality and Berry curvature in bilayer and four-layer MoS2 sliding ferroelectrics. These further affect the phonon angular momentum and magnetization under a temperature gradient and the phonon Hall effect under a magnetic field. Our work connects two emerging fields and opens up a new route to manipulating phonon chirality in transition-metal dichalcogenide materials through the sliding ferroelectric mechanism.
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Affiliation(s)
- Hao Chen
- Department of Physics, University of Science and Technology of China, Hefei 230026, China
- Phonon Engineering Research Center of Jiangsu Province, Center for Quantum Transport and Thermal Energy Science, Institute of Physics Frontiers and Interdisciplinary Sciences, School of Physics and Technology, Nanjing Normal University, Nanjing 210023, China
| | - Qianqian Wang
- Research Laboratory for Quantum Materials, Singapore University of Technology and Design, Singapore 487372, Singapore
| | - Xukun Feng
- Research Laboratory for Quantum Materials, Singapore University of Technology and Design, Singapore 487372, Singapore
| | - Weikang Wu
- Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials, Ministry of Education, Shandong University, Jinan 250061, China
| | - Lifa Zhang
- Phonon Engineering Research Center of Jiangsu Province, Center for Quantum Transport and Thermal Energy Science, Institute of Physics Frontiers and Interdisciplinary Sciences, School of Physics and Technology, Nanjing Normal University, Nanjing 210023, China
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7
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Man P, Huang L, Zhao J, Ly TH. Ferroic Phases in Two-Dimensional Materials. Chem Rev 2023; 123:10990-11046. [PMID: 37672768 DOI: 10.1021/acs.chemrev.3c00170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/08/2023]
Abstract
Two-dimensional (2D) ferroics, namely ferroelectric, ferromagnetic, and ferroelastic materials, are attracting rising interest due to their fascinating physical properties and promising functional applications. A variety of 2D ferroic phases, as well as 2D multiferroics and the novel 2D ferrovalleytronics/ferrotoroidics, have been recently predicted by theory, even down to the single atomic layers. Meanwhile, some of them have already been experimentally verified. In addition to the intrinsic 2D ferroics, appropriate stacking, doping, and defects can also artificially regulate the ferroic phases of 2D materials. Correspondingly, ferroic ordering in 2D materials exhibits enormous potential for future high density memory devices, energy conversion devices, and sensing devices, among other applications. In this paper, the recent research progresses on 2D ferroic phases are comprehensively reviewed, with emphasis on chemistry and structural origin of the ferroic properties. In addition, the promising applications of the 2D ferroics for information storage, optoelectronics, and sensing are also briefly discussed. Finally, we envisioned a few possible pathways for the future 2D ferroics research and development. This comprehensive overview on the 2D ferroic phases can provide an atlas for this field and facilitate further exploration of the intriguing new materials and physical phenomena, which will generate tremendous impact on future functional materials and devices.
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Affiliation(s)
- Ping Man
- Department of Chemistry and Center of Super-Diamond & Advanced Films (COSDAF), City University of Hong Kong, Kowloon, Hong Kong 999077, P. R. China
- City University of Hong Kong Shenzhen Research Institute, Shenzhen 518057, P. R. China
| | - Lingli Huang
- Department of Chemistry and Center of Super-Diamond & Advanced Films (COSDAF), City University of Hong Kong, Kowloon, Hong Kong 999077, P. R. China
- City University of Hong Kong Shenzhen Research Institute, Shenzhen 518057, P. R. China
| | - Jiong Zhao
- Department of Applied Physics, The Hong Kong Polytechnic University, Kowloon, Hong Kong 999077, P. R. China
- The Hong Kong Polytechnic University Shenzhen Research Institute, Shenzhen 518057, P. R. China
| | - Thuc Hue Ly
- Department of Chemistry and Center of Super-Diamond & Advanced Films (COSDAF), City University of Hong Kong, Kowloon, Hong Kong 999077, P. R. China
- City University of Hong Kong Shenzhen Research Institute, Shenzhen 518057, P. R. China
- Department of Chemistry and State Key Laboratory of Marine Pollution, City University of Hong Kong, Kowloon, Hong Kong 999077, P. R. China
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8
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Abramov AN, Chestnov IY, Alimova ES, Ivanova T, Mukhin IS, Krizhanovskii DN, Shelykh IA, Iorsh IV, Kravtsov V. Photoluminescence imaging of single photon emitters within nanoscale strain profiles in monolayer WSe 2. Nat Commun 2023; 14:5737. [PMID: 37714836 PMCID: PMC10504242 DOI: 10.1038/s41467-023-41292-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Accepted: 08/29/2023] [Indexed: 09/17/2023] Open
Abstract
Local deformation of atomically thin van der Waals materials provides a powerful approach to create site-controlled chip-compatible single-photon emitters (SPEs). However, the microscopic mechanisms underlying the formation of such strain-induced SPEs are still not fully clear, which hinders further efforts in their deterministic integration with nanophotonic structures for developing practical on-chip sources of quantum light. Here we investigate SPEs with single-photon purity up to 98% created in monolayer WSe2 via nanoindentation. Using photoluminescence imaging in combination with atomic force microscopy, we locate single-photon emitting sites on a deep sub-wavelength spatial scale and reconstruct the details of the surrounding local strain potential. The obtained results suggest that the origin of the observed single-photon emission is likely related to strain-induced spectral shift of dark excitonic states and their hybridization with localized states of individual defects.
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Affiliation(s)
- Artem N Abramov
- School of Physics and Engineering, ITMO University, Saint Petersburg, 197101, Russia
| | - Igor Y Chestnov
- School of Physics and Engineering, ITMO University, Saint Petersburg, 197101, Russia
| | - Ekaterina S Alimova
- Peter The Great St. Petersburg Polytechnic University, Saint Petersburg, 195251, Russia
| | - Tatiana Ivanova
- School of Physics and Engineering, ITMO University, Saint Petersburg, 197101, Russia
| | - Ivan S Mukhin
- School of Physics and Engineering, ITMO University, Saint Petersburg, 197101, Russia
- St. Petersburg Academic University, Saint Petersburg, 194021, Russia
| | | | - Ivan A Shelykh
- School of Physics and Engineering, ITMO University, Saint Petersburg, 197101, Russia
- Science Institute, University of Iceland, Dunhagi-3, IS-107, Reykjavik, Iceland
- Abrikosov Center for Theoretical Physics, MIPT, Dolgoprudnyi, Moscow Region, 141701, Russia
- Russian Quantum Center, Skolkovo, Moscow, 143025, Russia
| | - Ivan V Iorsh
- School of Physics and Engineering, ITMO University, Saint Petersburg, 197101, Russia
- Abrikosov Center for Theoretical Physics, MIPT, Dolgoprudnyi, Moscow Region, 141701, Russia
- Russian Quantum Center, Skolkovo, Moscow, 143025, Russia
| | - Vasily Kravtsov
- School of Physics and Engineering, ITMO University, Saint Petersburg, 197101, Russia.
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9
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Li WH, Lin JD, Lo PY, Peng GH, Hei CY, Chen SY, Cheng SJ. The Key Role of Non-Local Screening in the Environment-Insensitive Exciton Fine Structures of Transition-Metal Dichalcogenide Monolayers. NANOMATERIALS (BASEL, SWITZERLAND) 2023; 13:nano13111739. [PMID: 37299642 DOI: 10.3390/nano13111739] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Revised: 05/21/2023] [Accepted: 05/23/2023] [Indexed: 06/12/2023]
Abstract
In this work, we present a comprehensive theoretical and computational investigation of exciton fine structures of WSe2-monolayers, one of the best-known two-dimensional (2D) transition-metal dichalcogenides (TMDs), in various dielectric-layered environments by solving the first-principles-based Bethe-Salpeter equation. While the physical and electronic properties of atomically thin nanomaterials are normally sensitive to the variation of the surrounding environment, our studies reveal that the influence of the dielectric environment on the exciton fine structures of TMD-MLs is surprisingly limited. We point out that the non-locality of Coulomb screening plays a key role in suppressing the dielectric environment factor and drastically shrinking the fine structure splittings between bright exciton (BX) states and various dark-exciton (DX) states of TMD-MLs. The intriguing non-locality of screening in 2D materials can be manifested by the measurable non-linear correlation between the BX-DX splittings and exciton-binding energies by varying the surrounding dielectric environments. The revealed environment-insensitive exciton fine structures of TMD-ML suggest the robustness of prospective dark-exciton-based optoelectronics against the inevitable variation of the inhomogeneous dielectric environment.
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Affiliation(s)
- Wei-Hua Li
- Department of Electrophysics, National Yang Ming Chiao Tung University, Hsinchu 300, Taiwan
| | - Jhen-Dong Lin
- Department of Electrophysics, National Yang Ming Chiao Tung University, Hsinchu 300, Taiwan
| | - Ping-Yuan Lo
- Department of Electrophysics, National Yang Ming Chiao Tung University, Hsinchu 300, Taiwan
| | - Guan-Hao Peng
- Department of Electrophysics, National Yang Ming Chiao Tung University, Hsinchu 300, Taiwan
| | - Ching-Yu Hei
- Department of Electrophysics, National Yang Ming Chiao Tung University, Hsinchu 300, Taiwan
| | - Shao-Yu Chen
- Center of Condensed Matter Sciences, National Taiwan University, Taipei 106, Taiwan
- Center of Atomic Initiative for New Material, National Taiwan University, Taipei 106, Taiwan
| | - Shun-Jen Cheng
- Department of Electrophysics, National Yang Ming Chiao Tung University, Hsinchu 300, Taiwan
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10
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Hernández López P, Heeg S, Schattauer C, Kovalchuk S, Kumar A, Bock DJ, Kirchhof JN, Höfer B, Greben K, Yagodkin D, Linhart L, Libisch F, Bolotin KI. Strain control of hybridization between dark and localized excitons in a 2D semiconductor. Nat Commun 2022; 13:7691. [PMID: 36509779 PMCID: PMC9744834 DOI: 10.1038/s41467-022-35352-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Accepted: 11/30/2022] [Indexed: 12/14/2022] Open
Abstract
Mechanical strain is a powerful tuning knob for excitons, Coulomb-bound electron-hole complexes dominating optical properties of two-dimensional semiconductors. While the strain response of bright free excitons is broadly understood, the behaviour of dark free excitons (long-lived excitations that generally do not couple to light due to spin and momentum conservation) or localized excitons related to defects remains mostly unexplored. Here, we study the strain behaviour of these fragile many-body states on pristine suspended WSe2 kept at cryogenic temperatures. We find that under the application of strain, dark and localized excitons in monolayer WSe2-a prototypical 2D semiconductor-are brought into energetic resonance, forming a new hybrid state that inherits the properties of the constituent species. The characteristics of the hybridized state, including an order-of-magnitude enhanced light/matter coupling, avoided-crossing energy shifts, and strain tunability of many-body interactions, are all supported by first-principles calculations. The hybridized excitons reported here may play a critical role in the operation of single quantum emitters based on WSe2. Furthermore, the techniques we developed may be used to fingerprint unidentified excitonic states.
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Affiliation(s)
- Pablo Hernández López
- Humboldt-Universität zu Berlin, Institut für Physik and IRIS Adlershof, 12489, Berlin, Germany.
| | - Sebastian Heeg
- Humboldt-Universität zu Berlin, Institut für Physik and IRIS Adlershof, 12489, Berlin, Germany.
| | | | | | - Abhijeet Kumar
- Freie Universität Berlin, Department of Physics, 14195, Berlin, Germany
| | - Douglas J Bock
- Freie Universität Berlin, Department of Physics, 14195, Berlin, Germany
| | - Jan N Kirchhof
- Freie Universität Berlin, Department of Physics, 14195, Berlin, Germany
| | - Bianca Höfer
- Freie Universität Berlin, Department of Physics, 14195, Berlin, Germany
| | - Kyrylo Greben
- Freie Universität Berlin, Department of Physics, 14195, Berlin, Germany
| | - Denis Yagodkin
- Freie Universität Berlin, Department of Physics, 14195, Berlin, Germany
| | | | | | - Kirill I Bolotin
- Freie Universität Berlin, Department of Physics, 14195, Berlin, Germany.
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11
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High-lying valley-polarized trions in 2D semiconductors. Nat Commun 2022; 13:6980. [PMID: 36379952 PMCID: PMC9666447 DOI: 10.1038/s41467-022-33939-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Accepted: 10/07/2022] [Indexed: 11/16/2022] Open
Abstract
Optoelectronic functionalities of monolayer transition-metal dichalcogenide (TMDC) semiconductors are characterized by the emergence of externally tunable, correlated many-body complexes arising from strong Coulomb interactions. However, the vast majority of such states susceptible to manipulation has been limited to the region in energy around the fundamental bandgap. We report the observation of tightly bound, valley-polarized, UV-emissive trions in monolayer TMDC transistors: quasiparticles composed of an electron from a high-lying conduction band with negative effective mass, a hole from the first valence band, and an additional charge from a band-edge state. These high-lying trions have markedly different optical selection rules compared to band-edge trions and show helicity opposite to that of the excitation. An electrical gate controls both the oscillator strength and the detuning of the excitonic transitions, and therefore the Rabi frequency of the strongly driven three-level system, enabling excitonic quantum interference to be switched on and off in a deterministic fashion. Here, the authors observe tightly bound, valley-polarized, UV-emissive trions in monolayer transition metal dichalcogenide transistors. These are quasiparticles composed of an electron from a high-lying conduction band with negative effective mass, a hole from the first valence band, and an additional charge from a band-edge state.
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12
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Szmytkowski J. Quenching of bright and dark excitons via deep states in the presence of SRH recombination in 2D monolayer materials. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2022; 51:015601. [PMID: 36301700 DOI: 10.1088/1361-648x/ac9d7e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Accepted: 10/25/2022] [Indexed: 06/16/2023]
Abstract
Two-dimensional (2D) monolayer materials are interesting systems due to an existence of optically non-active dark excitonic states. In this work, we formulate a theoretical model of an excitonic Auger process which can occur together with the trap-assisted recombination in such 2D structures. The interactions of intravalley excitons (bright and spin-dark ones) and intervalley excitons (momentum-dark ones) with deep states located in the energy midgap have been taken into account. The explanation of this process is important for the understanding of excitonic and photoelectrical processes which can coexist in 2D materials, like transition metal dichalcogenides and perovskites.
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Affiliation(s)
- Jȩdrzej Szmytkowski
- Faculty of Applied Physics and Mathematics, Gdańsk University of Technology, Narutowicza 11/12, 80-233 Gdańsk, Poland
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13
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Dai D, Wang X, Yang J, Dang J, Yuan Y, Fu B, Xie X, Yang L, Xiao S, Shi S, Yan S, Zhu R, Zuo Z, Wang C, Jin K, Gong Q, Xu X. Single charge control of localized excitons in heterostructures with ferroelectric thin films and two-dimensional transition metal dichalcogenides. NANOSCALE 2022; 14:14537-14543. [PMID: 36185039 DOI: 10.1039/d2nr04119g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Single charge control of localized excitons (LXs) in two-dimensional transition metal dichalcogenides (TMDCs) is crucial for potential applications in quantum information processing and storage. However, traditional electrostatic doping method by applying metallic gates onto TMDCs may cause inhomogeneous charge distribution, optical quenching, and energy loss. Herein, by locally controlling the ferroelectric polarization of the ferroelectric thin film BiFeO3 (BFO) with a scanning probe, we can deterministically manipulate the doping type of monolayer WSe2 to achieve p-type and n-type doping. This nonvolatile approach can maintain the doping type and hold the localized excitonic charges for a long time without applied voltage. Our work demonstrated that the ferroelectric polarization of BFO can control the charges of LXs effectively. Neutral and charged LXs have been observed in different ferroelectric polarization regions, confirmed by magnetic optical measurement. Highly circular polarization degree with 90% photon emission from these quantum emitters was achieved in high magnetic fields. Controlling the single charge of LXs in a non-volatile way shows a great potential for deterministic photon emission with desired charge states for photonic long-term memory.
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Affiliation(s)
- Danjie Dai
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
- CAS Center for Excellence in Topological Quantum Computation and School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xinyan Wang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
- CAS Center for Excellence in Topological Quantum Computation and School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jingnan Yang
- State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics, School of Physics, Peking University, 100871 Beijing, China.
| | - Jianchen Dang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
- CAS Center for Excellence in Topological Quantum Computation and School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yu Yuan
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
- CAS Center for Excellence in Topological Quantum Computation and School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Bowen Fu
- State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics, School of Physics, Peking University, 100871 Beijing, China.
| | - Xin Xie
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
- CAS Center for Excellence in Topological Quantum Computation and School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Longlong Yang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
- CAS Center for Excellence in Topological Quantum Computation and School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Shan Xiao
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
- CAS Center for Excellence in Topological Quantum Computation and School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Shushu Shi
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
- CAS Center for Excellence in Topological Quantum Computation and School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Sai Yan
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
- CAS Center for Excellence in Topological Quantum Computation and School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Rui Zhu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
- CAS Center for Excellence in Topological Quantum Computation and School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhanchun Zuo
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
- CAS Center for Excellence in Topological Quantum Computation and School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Can Wang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
- CAS Center for Excellence in Topological Quantum Computation and School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
| | - Kuijuan Jin
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
- CAS Center for Excellence in Topological Quantum Computation and School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
| | - Qihuang Gong
- State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics, School of Physics, Peking University, 100871 Beijing, China.
| | - Xiulai Xu
- State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics, School of Physics, Peking University, 100871 Beijing, China.
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14
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Van Tuan D, Shi SF, Xu X, Crooker SA, Dery H. Six-Body and Eight-Body Exciton States in Monolayer WSe_{2}. PHYSICAL REVIEW LETTERS 2022; 129:076801. [PMID: 36018693 DOI: 10.1103/physrevlett.129.076801] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Accepted: 07/08/2022] [Indexed: 06/15/2023]
Abstract
In the archetypal monolayer semiconductor WSe_{2}, the distinct ordering of spin-polarized valleys (low-energy pockets) in the conduction band allows for studies of not only simple neutral excitons and charged excitons (i.e., trions), but also more complex many-body states that are predicted at higher electron densities. We discuss magneto-optical measurements of electron-rich WSe_{2} monolayers and interpret the spectral lines that emerge at high electron doping as optical transitions of six-body exciton states ("hexcitons") and eight-body exciton states ("oxcitons"). These many-body states emerge when a photoexcited electron-hole pair interacts simultaneously with multiple Fermi seas, each having distinguishable spin and valley quantum numbers. In addition, we explain the relations between dark trions and satellite optical transitions of hexcitons in the photoluminescence spectrum.
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Affiliation(s)
- Dinh Van Tuan
- Department of Electrical and Computer Engineering, University of Rochester, Rochester, New York 14627, USA
| | - Su-Fei Shi
- Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180, USA
- Department of Electrical, Computer and Systems Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180, USA
| | - Xiaodong Xu
- Department of Physics, University of Washington, Seattle, Washington 98195, USA
- Department of Materials Science and Engineering, University of Washington, Seattle, Washington 98195, USA
| | - Scott A Crooker
- National High Magnetic Field Laboratory, Los Alamos, New Mexico 87545, USA
| | - Hanan Dery
- Department of Electrical and Computer Engineering, University of Rochester, Rochester, New York 14627, USA
- Department of Physics and Astronomy, University of Rochester, Rochester, New York 14627, USA
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15
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Żuberek E, Majak M, Lubczyński J, Debus J, Watanabe K, Taniguchi T, Ho CH, Bryja L, Jadczak J. Upconversion photoluminescence excitation reveals exciton-trion and exciton-biexciton coupling in hBN/WS[Formula: see text]/hBN van der Waals heterostructures. Sci Rep 2022; 12:13699. [PMID: 35953508 PMCID: PMC9372078 DOI: 10.1038/s41598-022-18104-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Accepted: 08/05/2022] [Indexed: 11/10/2022] Open
Abstract
Monolayers of transition-metal dichalcogenides with direct band gap located at the binary [Formula: see text] points of the Brillouin zone are promising materials for applications in opto- and spin-electronics due to strongly enhanced Coulomb interactions and specific spin-valley properties. They furthermore represent a unique platform to study electron-electron and electron-phonon interactions in diverse exciton complexes. Here, we demonstrate processes in which the neutral biexciton and two negative trions, namely the spin-triplet and spin-singlet trions, upconvert light into a bright intravalley exciton in an hBN-encapsulated WS[Formula: see text] monolayer. We propose that the energy gains required in the polarized upconversion photoluminescence originate from different interactions including resonant optical phonons, a cooling of resident electrons and a non-local and an anisotropic electron-hole exchange, respectively. The temperature dependence (7-120 K) of the excitonic upconversion intensity obtained at excitation energies corresponding to the biexciton and trions provides insight into an increasing phonon population as well as a thermally enhanced electron scattering. Our study sheds new light on the understanding of excitonic spin and valley properties of van der Waals heterostructures and improves the understanding of photonic upconversion mechanisms in two-dimensional quantum materials.
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Affiliation(s)
- Ewa Żuberek
- Department of Experimental Physics, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland
| | - Martyna Majak
- Department of Experimental Physics, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland
| | - Jakub Lubczyński
- Department of Experimental Physics, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland
| | - Joerg Debus
- Department of Physics, TU Dortmund University, 44227 Dortmund, Germany
| | - Kenji Watanabe
- National Institute for Materials Science, Tsukuba, Ibaraki 305-0044 Japan
| | - Takashi Taniguchi
- National Institute for Materials Science, Tsukuba, Ibaraki 305-0044 Japan
| | - Ching-Hwa Ho
- Graduate Institute of Applied Science and Technology, National Taiwan University of Science and Technology, Taipei, 106 Taiwan
| | - Leszek Bryja
- Department of Experimental Physics, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland
| | - Joanna Jadczak
- Department of Experimental Physics, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland
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16
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Chang YW, Chang YC. Theory of magnetic-field effect on trions in two-dimensional materials. J Chem Phys 2022; 157:044104. [PMID: 35922350 DOI: 10.1063/5.0096834] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
In this work, we present a theoretical method to study the effect of magnetic field on trions in two-dimensional materials. The trion is modeled by a three-particle Schrödinger equation and the magnetic-field interaction is included by means of a vector potential in symmetric gauge. By using a coordinate transformation and a unitary transformation, the trion Hamiltonian can be converted into the sum of a translational term describing the Landau quantization for the trion center-of-mass motion, an internal term describing the trion binding, and a translational-internal coupling term depending linearly on the magnetic-field strength. The trion eigenenergy and wavefunction can then be calculated efficiently by using a variational method, and the quantum numbers of trions in magnetic fields can be assigned. The eigenenergies, binding energies, and correlation energies of three trion branches, which correspond to the ground-state trion and two excited-state trions solved from the trion Hamiltonian in zero magnetic field, are studied numerically in finite magnetic fields. The present method is applied to study the magnetic-field dependence of trion energy levels in hole-doped WSe2 monolayers. The binding energies and correlation energies of positive trions in WSe2 are investigated over a range of magnetic fields up to 25 T.
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Affiliation(s)
- Yao-Wen Chang
- Research Center for Applied Sciences, Academia Sinica, Taipei 11529, Taiwan
| | - Yia-Chung Chang
- Research Center for Applied Sciences, Academia Sinica, Taipei 11529, Taiwan
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17
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Bae S, Matsumoto K, Raebiger H, Shudo KI, Kim YH, Handegård ØS, Nagao T, Kitajima M, Sakai Y, Zhang X, Vajtai R, Ajayan P, Kono J, Takeda J, Katayama I. K-point longitudinal acoustic phonons are responsible for ultrafast intervalley scattering in monolayer MoSe 2. Nat Commun 2022; 13:4279. [PMID: 35879336 PMCID: PMC9314385 DOI: 10.1038/s41467-022-32008-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2022] [Accepted: 07/13/2022] [Indexed: 11/09/2022] Open
Abstract
In transition metal dichalcogenides, valley depolarization through intervalley carrier scattering by zone-edge phonons is often unavoidable. Although valley depolarization processes related to various acoustic phonons have been suggested, their optical verification is still vague due to nearly degenerate phonon frequencies on acoustic phonon branches at zone-edge momentums. Here we report an unambiguous phonon momentum determination of the longitudinal acoustic (LA) phonons at the K point, which are responsible for the ultrafast valley depolarization in monolayer MoSe2. Using sub-10-fs-resolution pump-probe spectroscopy, we observed coherent phonons signals at both even and odd-orders of zone-edge LA mode involved in intervalley carrier scattering process. Our phonon-symmetry analysis and first-principles calculations reveal that only the LA phonon at the K point, as opposed to the M point, can produce experimental odd-order LA phonon signals from its nonlinear optical modulation. This work will provide momentum-resolved descriptions of phonon-carrier intervalley scattering processes in valleytronic materials. Valley depolarization processes in 2D transition metal dichalcogenides have been linked to acoustic phonons, but optical verification is ambiguous, due to the nearly degenerate acoustic phonon frequencies at the zone-edge. Here, the authors determine the phonon momentum of the longitudinal acoustic (LA) phonons at the K point as responsible for the ultrafast valley depolarization in monolayer MoSe2.
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Affiliation(s)
- Soungmin Bae
- Laboratory for Materials and Structures, Tokyo Institute of Technology, Yokohama, Japan. .,Department of Physics, Graduate School of Engineering Science, Yokohama National University, Yokohama, Japan.
| | - Kana Matsumoto
- Department of Physics, Graduate School of Engineering Science, Yokohama National University, Yokohama, Japan
| | - Hannes Raebiger
- Department of Physics, Graduate School of Engineering Science, Yokohama National University, Yokohama, Japan
| | - Ken-Ichi Shudo
- Department of Physics, Graduate School of Engineering Science, Yokohama National University, Yokohama, Japan
| | - Yong-Hoon Kim
- School of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Korea
| | - Ørjan Sele Handegård
- International Center for Materials Nanoarchitectonics (MANA), National Institute for Materials Science (NIMS), Tsukuba, Japan.,Department of Condensed Matter Physics, Graduate School of Science, Hokkaido University, Sapporo, Japan
| | - Tadaaki Nagao
- International Center for Materials Nanoarchitectonics (MANA), National Institute for Materials Science (NIMS), Tsukuba, Japan.,Department of Condensed Matter Physics, Graduate School of Science, Hokkaido University, Sapporo, Japan
| | - Masahiro Kitajima
- Department of Physics, Graduate School of Engineering Science, Yokohama National University, Yokohama, Japan.,International Center for Materials Nanoarchitectonics (MANA), National Institute for Materials Science (NIMS), Tsukuba, Japan
| | - Yuji Sakai
- Institute of Laser Engineering, Osaka University, Osaka, Japan
| | - Xiang Zhang
- Department of Materials Science and NanoEngineering, Rice University, Houston, TX, USA
| | - Robert Vajtai
- Department of Materials Science and NanoEngineering, Rice University, Houston, TX, USA
| | - Pulickel Ajayan
- Department of Materials Science and NanoEngineering, Rice University, Houston, TX, USA
| | - Junichiro Kono
- Department of Materials Science and NanoEngineering, Rice University, Houston, TX, USA.,Department of Electrical and Computer Engineering, Rice University, Houston, TX, USA.,Department of Physics and Astronomy, Rice University, Houston, TX, USA
| | - Jun Takeda
- Department of Physics, Graduate School of Engineering Science, Yokohama National University, Yokohama, Japan.
| | - Ikufumi Katayama
- Department of Physics, Graduate School of Engineering Science, Yokohama National University, Yokohama, Japan.
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18
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Das S, Gupta G, Chatterjee S, Watanabe K, Taniguchi T, Majumdar K. Highly Nonlinear Biexcitonic Photocurrent from Ultrafast Interlayer Charge Transfer. ACS NANO 2022; 16:9728-9735. [PMID: 35604012 DOI: 10.1021/acsnano.2c03397] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Strong Coulomb interactions in monolayer semiconductors allow them to host optically active large many-body states, such as the five-particle state, charged biexciton. Strong nonlinear light absorption by the charged biexciton under spectral resonance, coupled with its charged nature, makes it intriguing for nonlinear photodetection─an area that is hitherto unexplored. Using the high built-in vertical electric field in an asymmetrically designed few-layer graphene encapsulated 1L-WS2 heterostructure, here we report a large, highly nonlinear photocurrent arising from the strong absorption by two charged biexciton species under zero external bias (self-powered mode). Time-resolved measurement reveals that the generated charged biexcitons transfer to the few-layer graphene in a time scale of sub-5 ps, indicating an ultrafast intrinsic limit of the photoresponse. By using single- and two-color photoluminescence excitation spectroscopy, we show that the two biexcitonic peaks originate from bright-dark and bright-bright exciton-trion combinations. Such innate nonlinearity in the photocurrent due to its biexcitonic origin, coupled with the ultrafast response due to swift interlayer charge transfer, exemplifies the promise of manipulating many-body effects in monolayers toward viable optoelectronic applications.
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Affiliation(s)
- Sarthak Das
- Department of Electrical Communication Engineering, Indian Institute of Science, Bangalore 560012, India
| | - Garima Gupta
- Department of Electrical Communication Engineering, Indian Institute of Science, Bangalore 560012, India
| | - Suman Chatterjee
- Department of Electrical Communication Engineering, Indian Institute of Science, Bangalore 560012, India
| | - Kenji Watanabe
- Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-044, Japan
| | - Takashi Taniguchi
- International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-044 Japan
| | - Kausik Majumdar
- Department of Electrical Communication Engineering, Indian Institute of Science, Bangalore 560012, India
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19
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Lo TW, Chen X, Zhang Z, Zhang Q, Leung CW, Zayats AV, Lei D. Plasmonic Nanocavity Induced Coupling and Boost of Dark Excitons in Monolayer WSe 2 at Room Temperature. NANO LETTERS 2022; 22:1915-1921. [PMID: 35225629 DOI: 10.1021/acs.nanolett.1c04360] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Spin-forbidden excitons in monolayer transition metal dichalcogenides are optically inactive at room temperature. Probing and manipulating these dark excitons are essential for understanding exciton spin relaxation and valley coherence of these 2D materials. Here, we show that the coupling of dark excitons to a metal nanoparticle-on-mirror cavity leads to plasmon-induced resonant emission with the intensity comparable to that of the spin-allowed bright excitons. A three-state quantum model combined with full-wave electrodynamic calculations reveals that the radiative decay rate of the dark excitons can be enhanced by nearly 6 orders of magnitude through the Purcell effect, therefore compensating its intrinsic nature of weak radiation. Our nanocavity approach provides a useful paradigm for understanding the room-temperature dynamics of dark excitons, potentially paving the road for employing dark exciton in quantum computing and nanoscale optoelectronics.
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Affiliation(s)
- Tsz Wing Lo
- Department of Materials Science and Engineering, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong S.A.R
- Department of Applied Physics, The Hong Kong Polytechnic University, 11 Yuk Choi Road, Hung Hom, Hong Kong S.A.R
| | - Xiaolin Chen
- Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, 11 Yuk Choi Road, Hung Hom, Hong Kong S.A.R
| | - Zhedong Zhang
- Department of Physics, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong S.A.R
| | - Qiang Zhang
- Department of Physics and Optoelectronics, Key Lab of Advanced Transducers and Intelligent Control System of Ministry of Education, Taiyuan University of Technology, Taiyuan 030024, China
| | - Chi Wah Leung
- Department of Applied Physics, The Hong Kong Polytechnic University, 11 Yuk Choi Road, Hung Hom, Hong Kong S.A.R
| | - Anatoly V Zayats
- Department of Physics and London Centre for Nanotechnology, King's College London, Strand, London WC2R 2LS, United Kingdom
| | - Dangyuan Lei
- Department of Materials Science and Engineering, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong S.A.R
- Department of Applied Physics, The Hong Kong Polytechnic University, 11 Yuk Choi Road, Hung Hom, Hong Kong S.A.R
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20
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Altaiary MM, Liu E, Liang CT, Hsiao FC, van Baren J, Taniguchi T, Watanabe K, Gabor NM, Chang YC, Lui CH. Electrically Switchable Intervalley Excitons with Strong Two-Phonon Scattering in Bilayer WSe 2. NANO LETTERS 2022; 22:1829-1835. [PMID: 35201774 DOI: 10.1021/acs.nanolett.1c01590] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
We report the observation of QΓ intervalley exciton in bilayer WSe2 devices encapsulated by boron nitride. The QΓ exciton resides at ∼18 meV below the QK exciton. The QΓ and QK excitons exhibit different Stark shifts under an out-of-plane electric field due to their different interlayer dipole moments. By controlling the electric field, we can switch their energy ordering and control which exciton dominates the luminescence of bilayer WSe2. Remarkably, both QΓ and QK excitons exhibit unusually strong two-phonon replicas, which are comparable to or even stronger than the one-phonon replicas. By detailed theoretical simulation, we reveal the existence of numerous (≥14) two-phonon scattering paths involving (nearly) resonant exciton-phonon scattering in bilayer WSe2. To our knowledge, such electric-field-switchable intervalley excitons with strong two-phonon replicas have not been found in any other two-dimensional semiconductors. These make bilayer WSe2 a distinctive valleytronic material with potential novel applications.
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Affiliation(s)
- Mashael M Altaiary
- Department of Physics and Astronomy, University of California, Riverside, California 92521, United States
- Department of Physics, University of Jeddah, Jeddah 23445, Saudi Arabia
| | - Erfu Liu
- Department of Physics and Astronomy, University of California, Riverside, California 92521, United States
| | - Ching-Tarng Liang
- Research Center for Applied Sciences, Academia Sinica, Taipei 11529, Taiwan
| | - Fu-Chen Hsiao
- Research Center for Applied Sciences, Academia Sinica, Taipei 11529, Taiwan
- Advanced Semiconductor Device and Integration Laboratory, Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Jeremiah van Baren
- Department of Physics and Astronomy, University of California, Riverside, California 92521, United States
| | - Takashi Taniguchi
- International Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science, 1-1 Namiki Tsukuba, Ibaraki 305-0044, Japan
| | - Kenji Watanabe
- Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Nathaniel M Gabor
- Department of Physics and Astronomy, University of California, Riverside, California 92521, United States
- Canadian Institute for Advanced Research, 661 University Avenue, MaRS Centre West Tower, Toronto, Ontario M5G 1M1, Canada
| | - Yia-Chung Chang
- Research Center for Applied Sciences, Academia Sinica, Taipei 11529, Taiwan
| | - Chun Hung Lui
- Department of Physics and Astronomy, University of California, Riverside, California 92521, United States
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21
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Jadczak J, Glazov M, Kutrowska-Girzycka J, Schindler JJ, Debus J, Ho CH, Watanabe K, Taniguchi T, Bayer M, Bryja L. Upconversion of Light into Bright Intravalley Excitons via Dark Intervalley Excitons in hBN-Encapsulated WSe 2 Monolayers. ACS NANO 2021; 15:19165-19174. [PMID: 34735768 PMCID: PMC8717626 DOI: 10.1021/acsnano.1c08286] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Accepted: 10/29/2021] [Indexed: 05/19/2023]
Abstract
Semiconducting monolayers of transition-metal dichalcogenides are outstanding platforms to study both electronic and phononic interactions as well as intra- and intervalley excitons and trions. These excitonic complexes are optically either active (bright) or inactive (dark) due to selection rules from spin or momentum conservation. Exploring ways of brightening dark excitons and trions has strongly been pursued in semiconductor physics. Here, we report on a mechanism in which a dark intervalley exciton upconverts light into a bright intravalley exciton in hBN-encapsulated WSe2 monolayers. Excitation spectra of upconverted photoluminescence reveals resonances at energies 34.5 and 46.0 meV below the neutral exciton in the nominal WSe2 transparency range. The required energy gains are theoretically explained by cooling of resident electrons or by exciton scattering with Λ- or K-valley phonons. Accordingly, an elevated temperature and a moderate concentration of resident electrons are necessary for observing the upconversion resonances. The interaction process observed between the inter- and intravalley excitons elucidates the importance of dark excitons for the optics of two-dimensional materials.
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Affiliation(s)
- Joanna Jadczak
- Department
of Experimental Physics, Wrocław University
of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland
- (J.J.)
| | | | - Joanna Kutrowska-Girzycka
- Department
of Experimental Physics, Wrocław University
of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland
| | | | - Joerg Debus
- Experimental
Physics 2, TU Dortmund University, 44227 Dortmund, Germany
| | - Ching-Hwa Ho
- Graduate
Institute of Applied Science and Technology, National Taiwan University of Science and Technology, Taipei 106, Taiwan
| | - Kenji Watanabe
- National
Institute for Materials Science, Tsukuba, Ibaraki 305-0044, Japan
| | - Takashi Taniguchi
- National
Institute for Materials Science, Tsukuba, Ibaraki 305-0044, Japan
| | - Manfred Bayer
- Experimental
Physics 2, TU Dortmund University, 44227 Dortmund, Germany
| | - Leszek Bryja
- Department
of Experimental Physics, Wrocław University
of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland
- (L.B.)
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22
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Abstract
We discover chiral phonons at the lowest energy bands in moiré superlattices. The moiré chiral phonons we uncover are the collective excitations of the stacking domains. Their origin is uniquely attributed to the stacking configurations whose interlayer binding energy breaks the C2z symmetry on the moiré length scale. Within elastic theory, we use a general symmetry analysis to provide a complete classification of van der Waals heterostructures in respect to hosting moiré chiral phonons and show the calculation for twisted MoS2 as an example. We present a low-energy effective model to qualitatively understand the moiré chiral phonons and show that it captures the essential physics remarkably well. Our result potentially opens up new possibilities in phononic twistronics as the moiré chiral phonons have high tunability, moiré scale wavelengths, excitation energies in only a few meV and can possibly be mechanically excited.
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Affiliation(s)
- Nishchay Suri
- Department of Physics, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
| | - Chong Wang
- Department of Materials Science and Engineering, University of Washington, Seattle, Washington 98195, United States
| | - Yinhan Zhang
- Department of Physics, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
| | - Di Xiao
- Department of Materials Science and Engineering, University of Washington, Seattle, Washington 98195, United States
- Department of Physics, University of Washington, Seattle, Washington 98195, United States
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23
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Liu E, van Baren J, Lu Z, Taniguchi T, Watanabe K, Smirnov D, Chang YC, Lui CH. Exciton-polaron Rydberg states in monolayer MoSe 2 and WSe 2. Nat Commun 2021; 12:6131. [PMID: 34675213 PMCID: PMC8531338 DOI: 10.1038/s41467-021-26304-w] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Accepted: 09/28/2021] [Indexed: 11/18/2022] Open
Abstract
Exciton polaron is a hypothetical many-body quasiparticle that involves an exciton dressed with a polarized electron-hole cloud in the Fermi sea. It has been evoked to explain the excitonic spectra of charged monolayer transition metal dichalcogenides, but the studies were limited to the ground state. Here we measure the reflection and photoluminescence of monolayer MoSe2 and WSe2 gating devices encapsulated by boron nitride. We observe gate-tunable exciton polarons associated with the 1 s–3 s exciton Rydberg states. The ground and excited exciton polarons exhibit comparable energy redshift (15~30 meV) from their respective bare excitons. The robust excited states contradict the trion picture because the trions are expected to dissociate in the excited states. When the Fermi sea expands, we observe increasingly severe suppression and steep energy shift from low to high exciton-polaron Rydberg states. Their gate-dependent energy shifts go beyond the trion description but match our exciton-polaron theory. Our experiment and theory demonstrate the exciton-polaron nature of both the ground and excited excitonic states in charged monolayer MoSe2 and WSe2. An exciton polaron is a quasiparticle composed of an exciton dressed with an electron-hole cloud, and this concept has been used to explain the ground excitonic states in charged monolayer transition metal dichalcogenides. Here the authors present experimental and theoretical evidence of exciton-polaron Rydberg states in monolayer MoSe2 and WSe2.
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Affiliation(s)
- Erfu Liu
- Department of Physics and Astronomy, University of California, Riverside, CA, 92521, USA
| | - Jeremiah van Baren
- Department of Physics and Astronomy, University of California, Riverside, CA, 92521, USA
| | - Zhengguang Lu
- National High Magnetic Field Laboratory, Tallahassee, FL, 32310, USA.,Department of Physics, Florida State University, Tallahassee, FL, 32310, USA
| | - Takashi Taniguchi
- International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki Tsukuba, Ibaraki, 305-0044, Japan
| | - Kenji Watanabe
- National Institute for Materials Science, 1-1 Namiki Tsukuba, Ibaraki, 305-0044, Japan
| | - Dmitry Smirnov
- National High Magnetic Field Laboratory, Tallahassee, FL, 32310, USA
| | - Yia-Chung Chang
- Research Center for Applied Sciences, Academia Sinica, Taipei, 11529, Taiwan.
| | - Chun Hung Lui
- Department of Physics and Astronomy, University of California, Riverside, CA, 92521, USA.
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24
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Chang YW, Chang YC. Variationally optimized orbital approach to trions in two-dimensional materials. J Chem Phys 2021; 155:024110. [PMID: 34266270 DOI: 10.1063/5.0057493] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
In this work, trions in two-dimensional (2D) space are studied by the variational method with trial wavefunctions being constructed by 2D slater-type orbitals. Via this method, trion energy levels and wavefunctions can be calculated efficiently with fairly good accuracy. We first apply this method to study trion energy levels in a 2D hydrogen-like system with respect to a wide range of mass ratios and screening lengths. We find that the ground-state trion is bound for the whole parameter range, and an excited-state trion with antisymmetric permutation of electrons with finite angular momentum is bound for large electron-hole mass ratios or long screening lengths. The binding energies of ground-state trions calculated by the present method agree well with those calculated by more sophisticated but computationally demanding methods. We then calculate trion binding energies in various monolayer transition metal dichalcogenides (TMDCs) by using this method with the inclusion of electron-hole exchange (EHX) interaction. For TMDCs, we found that the effect of EHX can be significant in determining the trion binding energy and the possible existence of stable excited-state trions.
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Affiliation(s)
- Yao-Wen Chang
- Research Center for Applied Sciences, Academia Sinica, Taipei 11529, Taiwan
| | - Yia-Chung Chang
- Research Center for Applied Sciences, Academia Sinica, Taipei 11529, Taiwan
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25
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Liu E, Barré E, van Baren J, Wilson M, Taniguchi T, Watanabe K, Cui YT, Gabor NM, Heinz TF, Chang YC, Lui CH. Signatures of moiré trions in WSe 2/MoSe 2 heterobilayers. Nature 2021; 594:46-50. [PMID: 34079140 DOI: 10.1038/s41586-021-03541-z] [Citation(s) in RCA: 45] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Accepted: 04/12/2021] [Indexed: 02/05/2023]
Abstract
Moiré superlattices formed by van der Waals materials can support a wide range of electronic phases, including Mott insulators1-4, superconductors5-10 and generalized Wigner crystals2. When excitons are confined by a moiré superlattice, a new class of exciton emerges, which holds promise for realizing artificial excitonic crystals and quantum optical effects11-16. When such moiré excitons are coupled to charge carriers, correlated states may arise. However, no experimental evidence exists for charge-coupled moiré exciton states, nor have their properties been predicted by theory. Here we report the optical signatures of trions coupled to the moiré potential in tungsten diselenide/molybdenum diselenide heterobilayers. The moiré trions show multiple sharp emission lines with a complex charge-density dependence, in stark contrast to the behaviour of conventional trions. We infer distinct contributions to the trion emission from radiative decay in which the remaining carrier resides in different moiré minibands. Variation of the trion features is observed in different devices and sample areas, indicating high sensitivity to sample inhomogeneity and variability. The observation of these trion features motivates further theoretical and experimental studies of higher-order electron correlation effects in moiré superlattices.
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Affiliation(s)
- Erfu Liu
- Department of Physics and Astronomy, University of California, Riverside, CA, USA
| | - Elyse Barré
- Department of Electrical Engineering, Stanford University, Stanford, CA, USA.,SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - Jeremiah van Baren
- Department of Physics and Astronomy, University of California, Riverside, CA, USA
| | - Matthew Wilson
- Department of Physics and Astronomy, University of California, Riverside, CA, USA
| | - Takashi Taniguchi
- International Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science (NIMS), Ibaraki, Japan
| | - Kenji Watanabe
- National Institute for Materials Science (NIMS), Ibaraki, Japan
| | - Yong-Tao Cui
- Department of Physics and Astronomy, University of California, Riverside, CA, USA
| | - Nathaniel M Gabor
- Department of Physics and Astronomy, University of California, Riverside, CA, USA.,Canadian Institute for Advanced Research, Toronto, Ontario, Canada
| | - Tony F Heinz
- SLAC National Accelerator Laboratory, Menlo Park, CA, USA.,Department of Applied Physics, Stanford University, Stanford, CA, USA
| | - Yia-Chung Chang
- Research Center for Applied Sciences, Academia Sinica, Taipei, Taiwan.
| | - Chun Hung Lui
- Department of Physics and Astronomy, University of California, Riverside, CA, USA.
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26
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Zinkiewicz M, Woźniak T, Kazimierczuk T, Kapuscinski P, Oreszczuk K, Grzeszczyk M, Bartoš M, Nogajewski K, Watanabe K, Taniguchi T, Faugeras C, Kossacki P, Potemski M, Babiński A, Molas MR. Excitonic Complexes in n-Doped WS 2 Monolayer. NANO LETTERS 2021; 21:2519-2525. [PMID: 33683895 PMCID: PMC7995249 DOI: 10.1021/acs.nanolett.0c05021] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 02/22/2021] [Indexed: 05/25/2023]
Abstract
We investigate the origin of emission lines apparent in the low-temperature photoluminescence spectra of n-doped WS2 monolayer embedded in hexagonal BN layers using external magnetic fields and first-principles calculations. Apart from the neutral A exciton line, all observed emission lines are related to the negatively charged excitons. Consequently, we identify emissions due to both the bright (singlet and triplet) and dark (spin- and momentum-forbidden) negative trions as well as the phonon replicas of the latter optically inactive complexes. The semidark trions and negative biexcitons are distinguished. On the basis of their experimentally extracted and theoretically calculated g-factors, we identify three distinct families of emissions due to exciton complexes in WS2: bright, intravalley, and intervalley dark. The g-factors of the spin-split subbands in both the conduction and valence bands are also determined.
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Affiliation(s)
- Małgorzata Zinkiewicz
- Institute
of Experimental Physics, Faculty of Physics, University of Warsaw, ul. Pasteura 5, 02-093 Warsaw, Poland
| | - Tomasz Woźniak
- Department
of Semiconductor Materials Engineering, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego
27, 50-370 Wrocław, Poland
| | - Tomasz Kazimierczuk
- Institute
of Experimental Physics, Faculty of Physics, University of Warsaw, ul. Pasteura 5, 02-093 Warsaw, Poland
| | - Piotr Kapuscinski
- Laboratoire
National des Champs Magnétiques Intenses, CNRS-UGA-UPS-INSA-EMFL, 25, avenue des Martyrs, 38042 Grenoble, France
- Department
of Experimental Physics, Wrocław University
of Science and Technology, Wybrzeze Wyspianskiego 27, 50-370 Wrocław, Poland
| | - Kacper Oreszczuk
- Institute
of Experimental Physics, Faculty of Physics, University of Warsaw, ul. Pasteura 5, 02-093 Warsaw, Poland
| | - Magdalena Grzeszczyk
- Institute
of Experimental Physics, Faculty of Physics, University of Warsaw, ul. Pasteura 5, 02-093 Warsaw, Poland
| | - Miroslav Bartoš
- Laboratoire
National des Champs Magnétiques Intenses, CNRS-UGA-UPS-INSA-EMFL, 25, avenue des Martyrs, 38042 Grenoble, France
- Central
European Institute of Technology, Brno University
of Technology, Purkyňova
656/123, 612 00 Brno, Czech Republic
| | - Karol Nogajewski
- Institute
of Experimental Physics, Faculty of Physics, University of Warsaw, ul. Pasteura 5, 02-093 Warsaw, Poland
| | - Kenji Watanabe
- Research
Center for Functional Materials, National
Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Takashi Taniguchi
- International
Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Clement Faugeras
- Laboratoire
National des Champs Magnétiques Intenses, CNRS-UGA-UPS-INSA-EMFL, 25, avenue des Martyrs, 38042 Grenoble, France
| | - Piotr Kossacki
- Institute
of Experimental Physics, Faculty of Physics, University of Warsaw, ul. Pasteura 5, 02-093 Warsaw, Poland
| | - Marek Potemski
- Institute
of Experimental Physics, Faculty of Physics, University of Warsaw, ul. Pasteura 5, 02-093 Warsaw, Poland
- Laboratoire
National des Champs Magnétiques Intenses, CNRS-UGA-UPS-INSA-EMFL, 25, avenue des Martyrs, 38042 Grenoble, France
| | - Adam Babiński
- Institute
of Experimental Physics, Faculty of Physics, University of Warsaw, ul. Pasteura 5, 02-093 Warsaw, Poland
| | - Maciej R. Molas
- Institute
of Experimental Physics, Faculty of Physics, University of Warsaw, ul. Pasteura 5, 02-093 Warsaw, Poland
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27
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Tebyetekerwa M, Zhang J, Xu Z, Truong TN, Yin Z, Lu Y, Ramakrishna S, Macdonald D, Nguyen HT. Mechanisms and Applications of Steady-State Photoluminescence Spectroscopy in Two-Dimensional Transition-Metal Dichalcogenides. ACS NANO 2020; 14:14579-14604. [PMID: 33155803 DOI: 10.1021/acsnano.0c08668] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Two-dimensional (2D) transition-metal dichalcogenide (TMD) semiconductors exhibit many important structural and optoelectronic properties, such as strong light-matter interactions, direct bandgaps tunable from visible to near-infrared regions, flexibility and atomic thickness, quantum-confinement effects, valley polarization possibilities, and so on. Therefore, they are regarded as a very promising class of materials for next-generation state-of-the-art nano/micro optoelectronic devices. To explore different applications and device structures based on 2D TMDs, intrinsic material properties, their relationships, and evolutions with fabrication parameters need to be deeply understood, very often through a combination of various characterization techniques. Among them, steady-state photoluminescence (PL) spectroscopy has been extensively employed. This class of techniques is fast, contactless, and nondestructive and can provide very high spatial resolution. Therefore, it can be used to obtain optoelectronic properties from samples of various sizes (from microns to centimeters) during the fabrication process without complex sample preparation. In this article, the mechanism and applications of steady-state PL spectroscopy in 2D TMDs are reviewed. The first part of this review details the physics of PL phenomena in semiconductors and common techniques to acquire and analyze PL spectra. The second part introduces various applications of PL spectroscopy in 2D TMDs. Finally, a broader perspective is discussed to highlight some limitations and untapped opportunities of PL spectroscopy in characterizing 2D TMDs.
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Affiliation(s)
- Mike Tebyetekerwa
- Research School of Electrical, Energy, and Materials Engineering, College of Engineering and Computer Science, The Australian National University, Canberra, Australian Capital Territory 2601, Australia
| | - Jian Zhang
- Research School of Electrical, Energy, and Materials Engineering, College of Engineering and Computer Science, The Australian National University, Canberra, Australian Capital Territory 2601, Australia
- Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China
| | - Zhen Xu
- Department of Chemical Engineering, Imperial College London, London SW7 2AZ, United Kingdom
| | - Thien N Truong
- Research School of Electrical, Energy, and Materials Engineering, College of Engineering and Computer Science, The Australian National University, Canberra, Australian Capital Territory 2601, Australia
| | - Zongyou Yin
- Research School of Chemistry, College of Science, The Australian National University, Canberra, Australian Capital Territory 2601, Australia
| | - Yuerui Lu
- Research School of Electrical, Energy, and Materials Engineering, College of Engineering and Computer Science, The Australian National University, Canberra, Australian Capital Territory 2601, Australia
| | - Seeram Ramakrishna
- Department of Mechanical Engineering, National University of Singapore, Singapore 119260, Singapore
| | - Daniel Macdonald
- Research School of Electrical, Energy, and Materials Engineering, College of Engineering and Computer Science, The Australian National University, Canberra, Australian Capital Territory 2601, Australia
| | - Hieu T Nguyen
- Research School of Electrical, Energy, and Materials Engineering, College of Engineering and Computer Science, The Australian National University, Canberra, Australian Capital Territory 2601, Australia
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28
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Zinkiewicz M, Slobodeniuk AO, Kazimierczuk T, Kapuściński P, Oreszczuk K, Grzeszczyk M, Bartos M, Nogajewski K, Watanabe K, Taniguchi T, Faugeras C, Kossacki P, Potemski M, Babiński A, Molas MR. Neutral and charged dark excitons in monolayer WS 2. NANOSCALE 2020; 12:18153-18159. [PMID: 32853305 DOI: 10.1039/d0nr04243a] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Low temperature and polarization resolved magneto-photoluminescence experiments are used to investigate the properties of dark excitons and dark trions in a monolayer of WS2 encapsulated in hexagonal BN (hBN). We find that this system is an n-type doped semiconductor and that dark trions dominate the emission spectrum. In line with previous studies on WSe2, we identify the Coulomb exchange interaction coupled neutral dark and grey excitons through their polarization properties, while an analogous effect is not observed for dark trions. Applying the magnetic field in both perpendicular and parallel configurations with respect to the monolayer plane, we determine the g-factor of dark trions to be g ∼ -8.6. Their decay rate is close to 0.5 ns, more than 2 orders of magnitude longer than that of bright excitons.
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Affiliation(s)
- M Zinkiewicz
- Institute of Experimental Physics, Faculty of Physics, University of Warsaw, ul. Pasteura 5, 02-093 Warsaw, Poland.
| | - A O Slobodeniuk
- Department of Condensed Matter Physics, Faculty of Mathematics and Physics, Charles University in Prague, Ke Karlovu 5, Praha 2 CZ-121 16, Czech Republic
| | - T Kazimierczuk
- Institute of Experimental Physics, Faculty of Physics, University of Warsaw, ul. Pasteura 5, 02-093 Warsaw, Poland.
| | - P Kapuściński
- Laboratoire National des Champs Magnétiques Intenses, CNRS-UGA-UPS-INSA-EMFL, 25, avenue des Martyrs, 38042 Grenoble, France and Department of Experimental Physics, Faculty of Fundamental Problems of Technology, Wrocław University of Science and Technology, ul. Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland
| | - K Oreszczuk
- Institute of Experimental Physics, Faculty of Physics, University of Warsaw, ul. Pasteura 5, 02-093 Warsaw, Poland.
| | - M Grzeszczyk
- Institute of Experimental Physics, Faculty of Physics, University of Warsaw, ul. Pasteura 5, 02-093 Warsaw, Poland.
| | - M Bartos
- Laboratoire National des Champs Magnétiques Intenses, CNRS-UGA-UPS-INSA-EMFL, 25, avenue des Martyrs, 38042 Grenoble, France and Central European Institute of Technology, Brno University of Technology, Purkyňova 656/123, 612 00 Brno, Czech Republic
| | - K Nogajewski
- Institute of Experimental Physics, Faculty of Physics, University of Warsaw, ul. Pasteura 5, 02-093 Warsaw, Poland.
| | - K Watanabe
- Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - T Taniguchi
- International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - C Faugeras
- Laboratoire National des Champs Magnétiques Intenses, CNRS-UGA-UPS-INSA-EMFL, 25, avenue des Martyrs, 38042 Grenoble, France
| | - P Kossacki
- Institute of Experimental Physics, Faculty of Physics, University of Warsaw, ul. Pasteura 5, 02-093 Warsaw, Poland.
| | - M Potemski
- Institute of Experimental Physics, Faculty of Physics, University of Warsaw, ul. Pasteura 5, 02-093 Warsaw, Poland. and Laboratoire National des Champs Magnétiques Intenses, CNRS-UGA-UPS-INSA-EMFL, 25, avenue des Martyrs, 38042 Grenoble, France
| | - A Babiński
- Institute of Experimental Physics, Faculty of Physics, University of Warsaw, ul. Pasteura 5, 02-093 Warsaw, Poland.
| | - M R Molas
- Institute of Experimental Physics, Faculty of Physics, University of Warsaw, ul. Pasteura 5, 02-093 Warsaw, Poland.
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29
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Wu YC, Samudrala S, McClung A, Taniguchi T, Watanabe K, Arbabi A, Yan J. Up- and Down-Conversion between Intra- and Intervalley Excitons in Waveguide Coupled Monolayer WSe 2. ACS NANO 2020; 14:10503-10509. [PMID: 32687318 DOI: 10.1021/acsnano.0c04397] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The presence of two spin-split valleys in monolayer (1L) transition metal dichalcogenide (TMD) semiconductors supports versatile exciton species classified by their spin and valley quantum numbers. While the spin-0 intravalley exciton, known as the "bright" exciton, is readily observable, other types of excitons, such as the spin-1 intravalley (spin-dark) and spin-0 intervalley (momentum-dark) excitons, are more difficult to access. Here we develop a waveguide coupled 1L tungsten diselenide (WSe2) device to probe these exciton species. In particular, TM coupling to the atomic layer's out-of-plane dipole moments enabled us to not only efficiently collect but also resonantly populate the spin-1 dark excitons, promising for developing devices with long valley lifetimes. Our work reveals several upconversion processes that bring out an intricate coupling network linking spin-0 and spin-1 intra- and intervalley excitons, demonstrating that intervalley scattering and spin-flip are very common processes in the atomic layer. These experimental results deepen our understanding of tungsten diselenide exciton physics and illustrate that planar photonic devices are capable of harnessing versatile exciton species in TMD semiconductors.
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Affiliation(s)
- Yueh-Chun Wu
- Department of Physics, University of Massachusetts Amherst, Amherst, Massachusetts 01003, United States
| | - Sarath Samudrala
- Department of Electrical and Computer Engineering, University of Massachusetts Amherst, Amherst, Massachusetts 01003, United States
| | - Andrew McClung
- Department of Electrical and Computer Engineering, University of Massachusetts Amherst, Amherst, Massachusetts 01003, United States
| | - Takashi Taniguchi
- International Center for Materials Nanoarchitectonics, National Institute for Materials Science, Tsukuba, Ibaraki 305-0044, Japan
| | - Kenji Watanabe
- Research Center for Functional Materials, National Institute for Materials Science, Tsukuba, Ibaraki 305-0044, Japan
| | - Amir Arbabi
- Department of Electrical and Computer Engineering, University of Massachusetts Amherst, Amherst, Massachusetts 01003, United States
| | - Jun Yan
- Department of Physics, University of Massachusetts Amherst, Amherst, Massachusetts 01003, United States
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