Pub Date : 2024-07-04DOI: 10.1038/s41566-024-01467-2
V. Jelic, S. Adams, M. Hassan, K. Cleland-Host, S. E. Ammerman, T. L. Cocker
Lightwave-driven terahertz scanning tunnelling microscopy (THz-STM) is capable of exploring ultrafast dynamics across a wide range of materials with ångström resolution (10−10 m). In contrast to scanning near-field optical microscopy, where photons scattered by the tip apex are analysed to access the local dielectric function on the nanoscale, THz-STM uses a strong-field single-cycle terahertz pulse to drive an ultrafast current across a tunnel junction, thereby probing the local density of electronic states. Yet, the terahertz field in a THz-STM junction may also be spectrally modified by the local electromagnetic response of the sample. Here we demonstrate atomic-scale terahertz time-domain spectroscopy by combining waveform sampling with terahertz scanning tunnelling spectroscopy to study a single gallium arsenide surface defect, which exhibits a strongly localized terahertz resonance and resembles the elusive DX centre. These results are based on a generally applicable and self-consistent approach for terahertz near-field waveform acquisition in a tunnel junction that can distinguish local sample properties from effects due to terahertz pulse coupling, enabling comprehensive near-field microscopy on the atomic scale. Ångström-scale terahertz time-domain spectroscopy is demonstrated in a lightwave-driven scanning tunnelling microscope. Employing a metal surface as a reference, local terahertz near-fields are used for spectroscopy of a single atom resonator defect in doped gallium arsenide.
{"title":"Atomic-scale terahertz time-domain spectroscopy","authors":"V. Jelic, S. Adams, M. Hassan, K. Cleland-Host, S. E. Ammerman, T. L. Cocker","doi":"10.1038/s41566-024-01467-2","DOIUrl":"10.1038/s41566-024-01467-2","url":null,"abstract":"Lightwave-driven terahertz scanning tunnelling microscopy (THz-STM) is capable of exploring ultrafast dynamics across a wide range of materials with ångström resolution (10−10 m). In contrast to scanning near-field optical microscopy, where photons scattered by the tip apex are analysed to access the local dielectric function on the nanoscale, THz-STM uses a strong-field single-cycle terahertz pulse to drive an ultrafast current across a tunnel junction, thereby probing the local density of electronic states. Yet, the terahertz field in a THz-STM junction may also be spectrally modified by the local electromagnetic response of the sample. Here we demonstrate atomic-scale terahertz time-domain spectroscopy by combining waveform sampling with terahertz scanning tunnelling spectroscopy to study a single gallium arsenide surface defect, which exhibits a strongly localized terahertz resonance and resembles the elusive DX centre. These results are based on a generally applicable and self-consistent approach for terahertz near-field waveform acquisition in a tunnel junction that can distinguish local sample properties from effects due to terahertz pulse coupling, enabling comprehensive near-field microscopy on the atomic scale. Ångström-scale terahertz time-domain spectroscopy is demonstrated in a lightwave-driven scanning tunnelling microscope. Employing a metal surface as a reference, local terahertz near-fields are used for spectroscopy of a single atom resonator defect in doped gallium arsenide.","PeriodicalId":18926,"journal":{"name":"Nature Photonics","volume":null,"pages":null},"PeriodicalIF":32.3,"publicationDate":"2024-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141546065","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-03DOI: 10.1038/s41566-024-01451-w
Tomer Bucher, Harel Nahari, Hanan Herzig Sheinfux, Ron Ruimy, Arthur Niedermayr, Raphael Dahan, Qinghui Yan, Yuval Adiv, Michael Yannai, Jialin Chen, Yaniv Kurman, Sang Tae Park, Daniel J. Masiel, Eli Janzen, James H. Edgar, Fabrizio Carbone, Guy Bartal, Shai Tsesses, Frank H. L. Koppens, Giovanni Maria Vanacore, Ido Kaminer
Accessing the low-energy non-equilibrium dynamics of materials and their polaritons with simultaneous high spatial and temporal resolution has been a bold frontier of electron microscopy in recent years. One of the main challenges lies in the ability to retrieve extremely weak signals and simultaneously disentangling the amplitude and phase information. Here we present free-electron Ramsey imaging—a microscopy approach based on light-induced electron modulation that enables the coherent amplification of optical near fields in electron imaging. We provide simultaneous time-, space- and phase-resolved measurements of a micro-drum made from a hexagonal boron nitride membrane, visualizing the sub-cycle dynamics of two-dimensional polariton wavepackets therein. The phase-resolved measurement reveals vortex–anti-vortex singularities on the polariton wavefronts, together with an intriguing phenomenon of a travelling wave mimicking the amplitude profile of a standing wave. Our experiments show a 20-fold coherent amplification of the near-field signal compared with conventional electron near-field imaging, resolving peak field intensities in the order of a few watts per square centimetre, corresponding to field amplitudes of a few kilovolts per metre. As a result, our work paves the way for the spatiotemporal electron microscopy of biological specimens and quantum materials, exciting yet delicate samples that are currently difficult to investigate. Free-electron Ramsey imaging enables space-, time- and phase-resolved electron imaging of weak optical near fields. Owing to its phase-resolving ability, this technique images chiral vortex–anti-vortex phase singularities of phonon-polariton modes in hexagonal boron nitride.
{"title":"Coherently amplified ultrafast imaging using a free-electron interferometer","authors":"Tomer Bucher, Harel Nahari, Hanan Herzig Sheinfux, Ron Ruimy, Arthur Niedermayr, Raphael Dahan, Qinghui Yan, Yuval Adiv, Michael Yannai, Jialin Chen, Yaniv Kurman, Sang Tae Park, Daniel J. Masiel, Eli Janzen, James H. Edgar, Fabrizio Carbone, Guy Bartal, Shai Tsesses, Frank H. L. Koppens, Giovanni Maria Vanacore, Ido Kaminer","doi":"10.1038/s41566-024-01451-w","DOIUrl":"10.1038/s41566-024-01451-w","url":null,"abstract":"Accessing the low-energy non-equilibrium dynamics of materials and their polaritons with simultaneous high spatial and temporal resolution has been a bold frontier of electron microscopy in recent years. One of the main challenges lies in the ability to retrieve extremely weak signals and simultaneously disentangling the amplitude and phase information. Here we present free-electron Ramsey imaging—a microscopy approach based on light-induced electron modulation that enables the coherent amplification of optical near fields in electron imaging. We provide simultaneous time-, space- and phase-resolved measurements of a micro-drum made from a hexagonal boron nitride membrane, visualizing the sub-cycle dynamics of two-dimensional polariton wavepackets therein. The phase-resolved measurement reveals vortex–anti-vortex singularities on the polariton wavefronts, together with an intriguing phenomenon of a travelling wave mimicking the amplitude profile of a standing wave. Our experiments show a 20-fold coherent amplification of the near-field signal compared with conventional electron near-field imaging, resolving peak field intensities in the order of a few watts per square centimetre, corresponding to field amplitudes of a few kilovolts per metre. As a result, our work paves the way for the spatiotemporal electron microscopy of biological specimens and quantum materials, exciting yet delicate samples that are currently difficult to investigate. Free-electron Ramsey imaging enables space-, time- and phase-resolved electron imaging of weak optical near fields. Owing to its phase-resolving ability, this technique images chiral vortex–anti-vortex phase singularities of phonon-polariton modes in hexagonal boron nitride.","PeriodicalId":18926,"journal":{"name":"Nature Photonics","volume":null,"pages":null},"PeriodicalIF":32.3,"publicationDate":"2024-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141495993","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
High-entropy materials consisting of disordered multiple components can exhibit enhanced materials properties compared with their individual constituents. Although various high-entropy materials have been developed based on the configurational disorder of mixed inorganic components, the potential of organic moieties for high-entropy structures remains underexplored. Here we report a family of high-entropy organic–inorganic hybrid perovskites for photovoltaic applications. By mixing different A-site organic cations with various alkyl chains, we obtain a hybrid crystal structure with ordered inorganic frameworks and disordered organic moieties, leading to increased entropy. The hybrid perovskite exhibits superior properties compared with its single-component counterpart, including increased resilience to structural transitions and heat stress. When used in solar cells, the high-entropy hybrid perovskite leads to devices with a power conversion efficiency of 25.7% (certified, 25.5%) for an inverted-cell architecture. Cells retain over 98% of their initial power conversion efficiency after 1,000 h of operation under continuous illumination (AM 1.5 G), with a linear extrapolation to the T90 value of 5,040 h. In particular, the structural disorder of this class of high-entropy materials can also reduce non-radiative recombinations for a wide range of perovskite composition, stoichiometry deviation, film-processing history and device architecture. This universal and error-tolerant strategy can, thus, benefit the production yield of perovskite solar cells in future industrial mass production. Given the rich chemistry of organic moieties and mixing configuration, this work may also open up more opportunities to tune the stability and optoelectronic properties of perovskite materials for photoelectric applications. High-entropy hybrid perovskites exhibit improved materials properties compared with their individual components. When employed in solar cells, champion devices achieve a certified power conversion efficiency of 25.5% and an extrapolated T90 lifetime of over 5,000 h under continuous light soaking.
{"title":"High-entropy hybrid perovskites with disordered organic moieties for perovskite solar cells","authors":"Yuan Tian, Xu Zhang, Ke Zhao, Xiaohe Miao, Tianqi Deng, Wei Fan, Donger Jin, Xuanyu Jiang, Shulin Zhong, Xiaonan Wang, Sisi Wang, Pengju Shi, Liuwen Tian, Libing Yao, Shaokuan Gong, Xuemeng Yu, Xingyu Gao, Zhong Chen, Xihan Chen, Yunhao Lu, Vinayak Shrote, Yang Yang, Deren Yang, Rui Wang, Jingjing Xue","doi":"10.1038/s41566-024-01468-1","DOIUrl":"10.1038/s41566-024-01468-1","url":null,"abstract":"High-entropy materials consisting of disordered multiple components can exhibit enhanced materials properties compared with their individual constituents. Although various high-entropy materials have been developed based on the configurational disorder of mixed inorganic components, the potential of organic moieties for high-entropy structures remains underexplored. Here we report a family of high-entropy organic–inorganic hybrid perovskites for photovoltaic applications. By mixing different A-site organic cations with various alkyl chains, we obtain a hybrid crystal structure with ordered inorganic frameworks and disordered organic moieties, leading to increased entropy. The hybrid perovskite exhibits superior properties compared with its single-component counterpart, including increased resilience to structural transitions and heat stress. When used in solar cells, the high-entropy hybrid perovskite leads to devices with a power conversion efficiency of 25.7% (certified, 25.5%) for an inverted-cell architecture. Cells retain over 98% of their initial power conversion efficiency after 1,000 h of operation under continuous illumination (AM 1.5 G), with a linear extrapolation to the T90 value of 5,040 h. In particular, the structural disorder of this class of high-entropy materials can also reduce non-radiative recombinations for a wide range of perovskite composition, stoichiometry deviation, film-processing history and device architecture. This universal and error-tolerant strategy can, thus, benefit the production yield of perovskite solar cells in future industrial mass production. Given the rich chemistry of organic moieties and mixing configuration, this work may also open up more opportunities to tune the stability and optoelectronic properties of perovskite materials for photoelectric applications. High-entropy hybrid perovskites exhibit improved materials properties compared with their individual components. When employed in solar cells, champion devices achieve a certified power conversion efficiency of 25.5% and an extrapolated T90 lifetime of over 5,000 h under continuous light soaking.","PeriodicalId":18926,"journal":{"name":"Nature Photonics","volume":null,"pages":null},"PeriodicalIF":32.3,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141475157","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-01DOI: 10.1038/s41566-024-01466-3
Yuduo Guo, Yuhan Hao, Sen Wan, Hao Zhang, Laiyu Zhu, Yi Zhang, Jiamin Wu, Qionghai Dai, Lu Fang
Turbulence is a complex and chaotic state of fluid motion. Atmospheric turbulence within the Earth’s atmosphere poses fundamental challenges for applications such as remote sensing, free-space optical communications and astronomical observation due to its rapid evolution across temporal and spatial scales. Conventional methods for studying atmospheric turbulence face hurdles in capturing the wide-field distribution of turbulence due to its transparency and anisoplanatism. Here we develop a light-field-based plug-and-play wide-field wavefront sensor (WWS), facilitating the direct observation of atmospheric turbulence over 1,100 arcsec at 30 Hz. The experimental measurements agreed with the von Kármán turbulence model, further verified using a differential image motion monitor. Attached to an 80 cm telescope, our WWS enables clear turbulence profiling of three layers below an altitude of 750 m and high-resolution aberration-corrected imaging without additional deformable mirrors. The WWS also enables prediction of the evolution of turbulence dynamics within 33 ms using a convolutional recurrent neural network with wide-field measurements, leading to more accurate pre-compensation of turbulence-induced errors during free-space optical communication. Wide-field sensing of dynamic turbulence wavefronts provides new opportunities for studying the evolution of turbulence in the broad field of atmospheric optics. A wide-field wavefront sensor consisting of a microlens array on the native image plane enables observation of atmospheric turbulence over a field of view of 1,100 arcsec at 30 Hz with an 80 cm telescope. With the aid of a neural network, turbulence can be predicted 33 ms in advance.
{"title":"Direct observation of atmospheric turbulence with a video-rate wide-field wavefront sensor","authors":"Yuduo Guo, Yuhan Hao, Sen Wan, Hao Zhang, Laiyu Zhu, Yi Zhang, Jiamin Wu, Qionghai Dai, Lu Fang","doi":"10.1038/s41566-024-01466-3","DOIUrl":"10.1038/s41566-024-01466-3","url":null,"abstract":"Turbulence is a complex and chaotic state of fluid motion. Atmospheric turbulence within the Earth’s atmosphere poses fundamental challenges for applications such as remote sensing, free-space optical communications and astronomical observation due to its rapid evolution across temporal and spatial scales. Conventional methods for studying atmospheric turbulence face hurdles in capturing the wide-field distribution of turbulence due to its transparency and anisoplanatism. Here we develop a light-field-based plug-and-play wide-field wavefront sensor (WWS), facilitating the direct observation of atmospheric turbulence over 1,100 arcsec at 30 Hz. The experimental measurements agreed with the von Kármán turbulence model, further verified using a differential image motion monitor. Attached to an 80 cm telescope, our WWS enables clear turbulence profiling of three layers below an altitude of 750 m and high-resolution aberration-corrected imaging without additional deformable mirrors. The WWS also enables prediction of the evolution of turbulence dynamics within 33 ms using a convolutional recurrent neural network with wide-field measurements, leading to more accurate pre-compensation of turbulence-induced errors during free-space optical communication. Wide-field sensing of dynamic turbulence wavefronts provides new opportunities for studying the evolution of turbulence in the broad field of atmospheric optics. A wide-field wavefront sensor consisting of a microlens array on the native image plane enables observation of atmospheric turbulence over a field of view of 1,100 arcsec at 30 Hz with an 80 cm telescope. With the aid of a neural network, turbulence can be predicted 33 ms in advance.","PeriodicalId":18926,"journal":{"name":"Nature Photonics","volume":null,"pages":null},"PeriodicalIF":32.3,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41566-024-01466-3.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141475270","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Deep tissue chemical imaging has a vital role in biological and medical applications. Current approaches suffer from water absorption and tissue scattering, which limits imaging depth to hundreds of micrometres. The shortwave infrared spectral window allows deep tissue imaging but typically features unsatisfactory spatial resolution or low detection sensitivity. Here we present a shortwave infrared photothermal (SWIP) microscope for millimetre-deep vibrational imaging with micrometre lateral resolution. By pumping the overtone transition of carbon–hydrogen bonds and probing the subsequent photothermal lens with shortwave infrared light, SWIP can obtain chemical contrast from 1 μm polymer particles located at 800 μm depth in a highly scattering phantom. The amplitude of the SWIP signal is shown to be 63 times larger than that of the optically probed photoacoustic signal. We further demonstrate that SWIP can resolve intracellular lipids across an intact tumour spheroid and the layered structure in thick liver, skin, brain and breast tissues. SWIP microscopy fills a gap in vibrational imaging with subcellular resolution and millimetre-level penetration, which heralds broad potential for life science and clinical applications. Shortwave infrared photothermal microscopy enables chemical imaging at millimetre depths with a micrometre spatial resolution in tissue-mimicking phantoms, intact tumour spheroids and various biological tissues.
{"title":"Millimetre-deep micrometre-resolution vibrational imaging by shortwave infrared photothermal microscopy","authors":"Hongli Ni, Yuhao Yuan, Mingsheng Li, Yifan Zhu, Xiaowei Ge, Jiaze Yin, Chinmayee Prabhu Dessai, Le Wang, Ji-Xin Cheng","doi":"10.1038/s41566-024-01463-6","DOIUrl":"10.1038/s41566-024-01463-6","url":null,"abstract":"Deep tissue chemical imaging has a vital role in biological and medical applications. Current approaches suffer from water absorption and tissue scattering, which limits imaging depth to hundreds of micrometres. The shortwave infrared spectral window allows deep tissue imaging but typically features unsatisfactory spatial resolution or low detection sensitivity. Here we present a shortwave infrared photothermal (SWIP) microscope for millimetre-deep vibrational imaging with micrometre lateral resolution. By pumping the overtone transition of carbon–hydrogen bonds and probing the subsequent photothermal lens with shortwave infrared light, SWIP can obtain chemical contrast from 1 μm polymer particles located at 800 μm depth in a highly scattering phantom. The amplitude of the SWIP signal is shown to be 63 times larger than that of the optically probed photoacoustic signal. We further demonstrate that SWIP can resolve intracellular lipids across an intact tumour spheroid and the layered structure in thick liver, skin, brain and breast tissues. SWIP microscopy fills a gap in vibrational imaging with subcellular resolution and millimetre-level penetration, which heralds broad potential for life science and clinical applications. Shortwave infrared photothermal microscopy enables chemical imaging at millimetre depths with a micrometre spatial resolution in tissue-mimicking phantoms, intact tumour spheroids and various biological tissues.","PeriodicalId":18926,"journal":{"name":"Nature Photonics","volume":null,"pages":null},"PeriodicalIF":32.3,"publicationDate":"2024-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141448227","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-19DOI: 10.1038/s41566-024-01458-3
Hwan-Hee Cho, Sebastian Gorgon, Giacomo Londi, Samuele Giannini, Changsoon Cho, Pratyush Ghosh, Claire Tonnelé, David Casanova, Yoann Olivier, Tomi K. Baikie, Feng Li, David Beljonne, Neil C. Greenham, Richard H. Friend, Emrys W. Evans
The development of luminescent organic radicals has resulted in materials with excellent optical properties for near-infrared emission. Applications of light generation in this range span from bioimaging to surveillance. Although the unpaired electron arrangements of radicals enable efficient radiative transitions within the doublet-spin manifold in organic light-emitting diodes, their performance is limited by non-radiative pathways introduced in electroluminescence. Here we present a host–guest design for organic light-emitting diodes that exploits energy transfer with up to 9.6% external quantum efficiency for 800 nm emission. The tris(2,4,6-trichlorophenyl)methyl-triphenyl-amine radical guest is energy-matched to the triplet state in a charge-transporting anthracene-derivative host. We show from optical spectroscopy and quantum-chemical modelling that reversible host–guest triplet–doublet energy transfer allows efficient harvesting of host triplet excitons. Exploiting the energy transfer between the host triplet states and spin doublet exciton states of a radical organic emitter enables near-infrared organic light-emitting diodes with an external quantum efficiency up to 9.6% at an emission wavelength of 800 nm.
{"title":"Efficient near-infrared organic light-emitting diodes with emission from spin doublet excitons","authors":"Hwan-Hee Cho, Sebastian Gorgon, Giacomo Londi, Samuele Giannini, Changsoon Cho, Pratyush Ghosh, Claire Tonnelé, David Casanova, Yoann Olivier, Tomi K. Baikie, Feng Li, David Beljonne, Neil C. Greenham, Richard H. Friend, Emrys W. Evans","doi":"10.1038/s41566-024-01458-3","DOIUrl":"10.1038/s41566-024-01458-3","url":null,"abstract":"The development of luminescent organic radicals has resulted in materials with excellent optical properties for near-infrared emission. Applications of light generation in this range span from bioimaging to surveillance. Although the unpaired electron arrangements of radicals enable efficient radiative transitions within the doublet-spin manifold in organic light-emitting diodes, their performance is limited by non-radiative pathways introduced in electroluminescence. Here we present a host–guest design for organic light-emitting diodes that exploits energy transfer with up to 9.6% external quantum efficiency for 800 nm emission. The tris(2,4,6-trichlorophenyl)methyl-triphenyl-amine radical guest is energy-matched to the triplet state in a charge-transporting anthracene-derivative host. We show from optical spectroscopy and quantum-chemical modelling that reversible host–guest triplet–doublet energy transfer allows efficient harvesting of host triplet excitons. Exploiting the energy transfer between the host triplet states and spin doublet exciton states of a radical organic emitter enables near-infrared organic light-emitting diodes with an external quantum efficiency up to 9.6% at an emission wavelength of 800 nm.","PeriodicalId":18926,"journal":{"name":"Nature Photonics","volume":null,"pages":null},"PeriodicalIF":32.3,"publicationDate":"2024-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41566-024-01458-3.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141425363","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-18DOI: 10.1038/s41566-024-01435-w
L. H. Fowler-Gerace, Zhiwen Zhou, E. A. Szwed, D. J. Choksy, L. V. Butov
Long lifetimes of spatially indirect excitons (IXs), also known as interlayer excitons, allow implementing both quantum exciton systems and long-range exciton transport. The van der Waals heterostructures composed of atomically thin layers of transition-metal dichalcogenides offer the opportunity to explore IXs in moiré superlattices. IX transport in transition-metal dichalcogenide heterostructures was intensively studied and diffusive IX transport with 1/e decay distances up to ~4 μm was realized. Here, in a MoSe2/WSe2 heterostructure, we present the IX long-range transport with 1/e decay distances reaching and exceeding 100 μm. The IX long-range transport vanishes at temperatures above ~10 K. With increasing IX density, IX localization followed by IX long-range transport and IX re-entrant localization are observed. The non-monotonic dependence of IX transport on density is in qualitative agreement with the Bose–Hubbard theory prediction for superfluid and insulating phases in periodic potentials of moiré superlattices. Spatial distribution of the photoluminescence of interlayer excitons in van der Waals heterostructures comprising MoSe2 and WSe2 monolayers and encapsulated in rather thick hexagonal boron nitride is investigated, revealing interlayer exciton long-range transport with 1/e decay distances reaching and exceeding 100 μm.
空间间接激子（IXs）（也称为层间激子）的长寿命允许实现量子激子系统和长程激子传输。由过渡金属二卤化物原子薄层组成的范德华异质结构为探索摩尔超晶格中的 IX 提供了机会。我们对过渡金属二掺杂异质结构中的 IX 传输进行了深入研究，并实现了 IX 的扩散传输，其 1/e 衰变距离可达 ~4 μm。在这里，我们在 MoSe2/WSe2 异质结构中展示了 IX 长程传输，其 1/e 衰变距离达到并超过 100 μm。随着 IX 密度的增加，可以观察到 IX 局域化，然后是 IX 长程输运和 IX 再中心局域化。IX 传输对密度的非单调依赖性与玻色-哈伯德理论对摩尔超晶格周期势中超流体和绝缘相的预测在性质上是一致的。
{"title":"Transport and localization of indirect excitons in a van der Waals heterostructure","authors":"L. H. Fowler-Gerace, Zhiwen Zhou, E. A. Szwed, D. J. Choksy, L. V. Butov","doi":"10.1038/s41566-024-01435-w","DOIUrl":"10.1038/s41566-024-01435-w","url":null,"abstract":"Long lifetimes of spatially indirect excitons (IXs), also known as interlayer excitons, allow implementing both quantum exciton systems and long-range exciton transport. The van der Waals heterostructures composed of atomically thin layers of transition-metal dichalcogenides offer the opportunity to explore IXs in moiré superlattices. IX transport in transition-metal dichalcogenide heterostructures was intensively studied and diffusive IX transport with 1/e decay distances up to ~4 μm was realized. Here, in a MoSe2/WSe2 heterostructure, we present the IX long-range transport with 1/e decay distances reaching and exceeding 100 μm. The IX long-range transport vanishes at temperatures above ~10 K. With increasing IX density, IX localization followed by IX long-range transport and IX re-entrant localization are observed. The non-monotonic dependence of IX transport on density is in qualitative agreement with the Bose–Hubbard theory prediction for superfluid and insulating phases in periodic potentials of moiré superlattices. Spatial distribution of the photoluminescence of interlayer excitons in van der Waals heterostructures comprising MoSe2 and WSe2 monolayers and encapsulated in rather thick hexagonal boron nitride is investigated, revealing interlayer exciton long-range transport with 1/e decay distances reaching and exceeding 100 μm.","PeriodicalId":18926,"journal":{"name":"Nature Photonics","volume":null,"pages":null},"PeriodicalIF":32.3,"publicationDate":"2024-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141334408","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-17DOI: 10.1038/s41566-024-01460-9
Hongbing Cai, Abdullah Rasmita, Ruihua He, Zhaowei Zhang, Qinghai Tan, Disheng Chen, Naizhou Wang, Zhao Mu, John J. H. Eng, Yongzhi She, Nan Pan, Qian Wang, Zhaogang Dong, Xiaoping Wang, Juan Wang, Yansong Miao, Ranjan Singh, Cheng-Wei Qiu, Xiaogang Liu, Weibo Gao
Achieving unity quantum efficiency in single-photon emitters (SPEs) is a holy grail in quantum information science. Through plasmonic coupling it is possible to increase the quantum efficiency of SPEs by increasing the radiative decay rate, but to approach unity quantum efficiency, non-radiative decay must be mitigated. Here we show that non-radiative decay in two-dimensional WSe2 quantum emitters can be electrically suppressed through charge depletion by using dual gate configurations under a large electric field. In this condition, for site-controlled SPEs in WSe2 coupled to gold nanogaps, the SPE transition quantum efficiency after gating is increased to 76.4 ± 14.6% on average, with some SPEs reaching near-unity (more than 90%) quantum efficiency. This study provides a new approach for tuning SPEs with an applied gate voltage and motivates further theoretical and experimental studies of SPE enhancement on vertically aligned nanogaps. Non-radiative decay in two-dimensional WSe2 quantum emitters is electrically suppressed through charge depletion using dual gate configurations. The single-photon emitter transition quantum efficiency after gating is increased to 76.4 ± 14.6% on average.
{"title":"Charge-depletion-enhanced WSe2 quantum emitters on gold nanogap arrays with near-unity quantum efficiency","authors":"Hongbing Cai, Abdullah Rasmita, Ruihua He, Zhaowei Zhang, Qinghai Tan, Disheng Chen, Naizhou Wang, Zhao Mu, John J. H. Eng, Yongzhi She, Nan Pan, Qian Wang, Zhaogang Dong, Xiaoping Wang, Juan Wang, Yansong Miao, Ranjan Singh, Cheng-Wei Qiu, Xiaogang Liu, Weibo Gao","doi":"10.1038/s41566-024-01460-9","DOIUrl":"10.1038/s41566-024-01460-9","url":null,"abstract":"Achieving unity quantum efficiency in single-photon emitters (SPEs) is a holy grail in quantum information science. Through plasmonic coupling it is possible to increase the quantum efficiency of SPEs by increasing the radiative decay rate, but to approach unity quantum efficiency, non-radiative decay must be mitigated. Here we show that non-radiative decay in two-dimensional WSe2 quantum emitters can be electrically suppressed through charge depletion by using dual gate configurations under a large electric field. In this condition, for site-controlled SPEs in WSe2 coupled to gold nanogaps, the SPE transition quantum efficiency after gating is increased to 76.4 ± 14.6% on average, with some SPEs reaching near-unity (more than 90%) quantum efficiency. This study provides a new approach for tuning SPEs with an applied gate voltage and motivates further theoretical and experimental studies of SPE enhancement on vertically aligned nanogaps. Non-radiative decay in two-dimensional WSe2 quantum emitters is electrically suppressed through charge depletion using dual gate configurations. The single-photon emitter transition quantum efficiency after gating is increased to 76.4 ± 14.6% on average.","PeriodicalId":18926,"journal":{"name":"Nature Photonics","volume":null,"pages":null},"PeriodicalIF":32.3,"publicationDate":"2024-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141333530","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-14DOI: 10.1038/s41566-024-01461-8
Yang Zhou, Zhengfeng Guo, Honggang Gu, Yanqiang Li, Yipeng Song, Shiyuan Liu, Maochun Hong, Sangen Zhao, Junhua Luo
Optical anisotropy, a spatially asymmetric light–matter interaction that manifests itself as birefringence and dichroism, is paramount for manipulating light polarization in modern optics. So far, various natural birefringent crystals are widely used, but their birefringence is limited to <0.3. Here we demonstrate a solution-processable natural crystal C3H8N6I6·3H2O with giant birefringence up to 2.8 within the visible to infrared spectral region. Combining critical point analysis and the first-principles calculations, we reveal that this giant optical anisotropy mainly comes from the linear (I3)− structural units in a parallel arrangement, which maximizes the difference of polarizability along the different crystallographic axes. This work highlights the potential of natural polyiodide crystals as an outstanding platform to satisfy the increasing demand for photonic applications that exploit polarization in optical communication, three-dimensional imaging, ultrahigh-resolution sensing and other tasks. A crystal with giant birefringence in the visible and infrared could benefit applications that rely on manipulating optical polarization.
{"title":"A solution-processable natural crystal with giant optical anisotropy for efficient manipulation of light polarization","authors":"Yang Zhou, Zhengfeng Guo, Honggang Gu, Yanqiang Li, Yipeng Song, Shiyuan Liu, Maochun Hong, Sangen Zhao, Junhua Luo","doi":"10.1038/s41566-024-01461-8","DOIUrl":"10.1038/s41566-024-01461-8","url":null,"abstract":"Optical anisotropy, a spatially asymmetric light–matter interaction that manifests itself as birefringence and dichroism, is paramount for manipulating light polarization in modern optics. So far, various natural birefringent crystals are widely used, but their birefringence is limited to <0.3. Here we demonstrate a solution-processable natural crystal C3H8N6I6·3H2O with giant birefringence up to 2.8 within the visible to infrared spectral region. Combining critical point analysis and the first-principles calculations, we reveal that this giant optical anisotropy mainly comes from the linear (I3)− structural units in a parallel arrangement, which maximizes the difference of polarizability along the different crystallographic axes. This work highlights the potential of natural polyiodide crystals as an outstanding platform to satisfy the increasing demand for photonic applications that exploit polarization in optical communication, three-dimensional imaging, ultrahigh-resolution sensing and other tasks. A crystal with giant birefringence in the visible and infrared could benefit applications that rely on manipulating optical polarization.","PeriodicalId":18926,"journal":{"name":"Nature Photonics","volume":null,"pages":null},"PeriodicalIF":32.3,"publicationDate":"2024-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141319987","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-14DOI: 10.1038/s41566-024-01462-7
Xuchen Shan, Lei Ding, Dajing Wang, Shihui Wen, Jinlong Shi, Chaohao Chen, Yang Wang, Hongyan Zhu, Zhaocun Huang, Shen S. J. Wang, Xiaolan Zhong, Baolei Liu, Peter John Reece, Wei Ren, Weichang Hao, Xunyu Lu, Jie Lu, Qian Peter Su, Lingqian Chang, Lingdong Sun, Dayong Jin, Lei Jiang, Fan Wang
Precise force measurement is critical to probe biological events and physics processes, spanning from molecular motor’s motion to the Casimir effect, as well as the detection of gravitational waves. Yet, despite extensive technological developments, the three-dimensional nanoscale measurement of weak forces in aqueous solutions still faces major challenges. Techniques that rely on optically trapped nanoprobes are of significant potential but are beset with limitations, including probe heating induced by high trapping power, undetectable scattering signals and localization errors. Here we report the measurement of the long-distance interaction force in aqueous solutions with a minimum detected force value of 108.2 ± 510.0 attonewton. To achieve this, we develop a super-resolved photonic force microscope based on optically trapped lanthanide-doped nanoparticles coupled with nanoscale three-dimensional tracking-based force sensing. The tracking method leverages neural-network-empowered super-resolution localization, where the position of the force probe is extracted from the optical-astigmatism-modified point spread function. We achieve a force sensitivity down to 1.8 fN Hz–1/2, which approaches the nanoscale thermal limit. We experimentally measure electrophoresis forces acting on single nanoparticles as well as the surface-induced interaction force on a single nanoparticle. This work opens the avenue of nanoscale thermally limited force sensing and offers new opportunities for detecting sub-femtonewton forces over long distances and biomechanical forces at the single-molecule level. Super-resolved photonic force microscopy employs the fluorescence of lanthanide-doped nanoparticles as a force probe, enabling the measurement of sub-femtonewton forces with a sensitivity of 1.8 fN Hz–1/2, approaching the thermal limit.
{"title":"Sub-femtonewton force sensing in solution by super-resolved photonic force microscopy","authors":"Xuchen Shan, Lei Ding, Dajing Wang, Shihui Wen, Jinlong Shi, Chaohao Chen, Yang Wang, Hongyan Zhu, Zhaocun Huang, Shen S. J. Wang, Xiaolan Zhong, Baolei Liu, Peter John Reece, Wei Ren, Weichang Hao, Xunyu Lu, Jie Lu, Qian Peter Su, Lingqian Chang, Lingdong Sun, Dayong Jin, Lei Jiang, Fan Wang","doi":"10.1038/s41566-024-01462-7","DOIUrl":"10.1038/s41566-024-01462-7","url":null,"abstract":"Precise force measurement is critical to probe biological events and physics processes, spanning from molecular motor’s motion to the Casimir effect, as well as the detection of gravitational waves. Yet, despite extensive technological developments, the three-dimensional nanoscale measurement of weak forces in aqueous solutions still faces major challenges. Techniques that rely on optically trapped nanoprobes are of significant potential but are beset with limitations, including probe heating induced by high trapping power, undetectable scattering signals and localization errors. Here we report the measurement of the long-distance interaction force in aqueous solutions with a minimum detected force value of 108.2 ± 510.0 attonewton. To achieve this, we develop a super-resolved photonic force microscope based on optically trapped lanthanide-doped nanoparticles coupled with nanoscale three-dimensional tracking-based force sensing. The tracking method leverages neural-network-empowered super-resolution localization, where the position of the force probe is extracted from the optical-astigmatism-modified point spread function. We achieve a force sensitivity down to 1.8 fN Hz–1/2, which approaches the nanoscale thermal limit. We experimentally measure electrophoresis forces acting on single nanoparticles as well as the surface-induced interaction force on a single nanoparticle. This work opens the avenue of nanoscale thermally limited force sensing and offers new opportunities for detecting sub-femtonewton forces over long distances and biomechanical forces at the single-molecule level. Super-resolved photonic force microscopy employs the fluorescence of lanthanide-doped nanoparticles as a force probe, enabling the measurement of sub-femtonewton forces with a sensitivity of 1.8 fN Hz–1/2, approaching the thermal limit.","PeriodicalId":18926,"journal":{"name":"Nature Photonics","volume":null,"pages":null},"PeriodicalIF":32.3,"publicationDate":"2024-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141319791","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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