物理与天体物理最新文献

{"title":"Fabrication and SERS enhancement study of composite materials based on MoS2 and gold/silver nano particles membrane structure modified AAO","authors":"Zezheng Zhang,&nbsp;Yuanze Xu,&nbsp;Jian Shi,&nbsp;Weihao Liu,&nbsp;Shouzhen Jiang,&nbsp;Jie Pan","doi":"10.1016/j.optlastec.2025.113631","DOIUrl":"10.1016/j.optlastec.2025.113631","url":null,"abstract":"<div><div>The aim of this study is to develop a composite substrate for surface-enhanced Raman scattering (SERS) applications by utilizing a PMMA inverted anodic aluminum oxide (AAO) nanostructure array, with a modified MoS₂ film as an interlayer between the gold nanofilm (Au film) and silver nanoparticles (AgNPs). The substrate not only possesses the electromagnetic enhancement mechanism (EM), but also introduces the chemical enhancement mechanism (CM) of MoS₂ and its Raman internal standard characteristics. Utilizing the properties of hyperbolic metamaterials (HMM) to support high-wave-vector body plasmon polaritons (BPP), with AgNPs as the external coupling structure, the large-wave-vector scattering light conducted within the nanostructured array resonator excites the BPP in the HMM, expanding the energy into the gap of the AgNPs. This energy further couples with the local surface plasmon polaritons (LSP) on the surface, generating a high-density “hotspot” on the surface. Through a novel reverse fabrication method, we successfully fabricated a three-dimensional (3D) arrayed nano-composite architecture and used it as a flexible SERS sensor, which can be easily applied to large-scale manufacturing. Finally, experimental verification demonstrated the excellent performance of this substrate. The limits of detection (LOD) for the probe molecules R6G and CV were found to be 6.93 × 10^-12 M and 5.16 × 10^-11 M, respectively. Additionally, in situ detection of CV on seafood surfaces resulted in a LOD of 3.78 × 10^-6 M. Therefore, we believe that this flexible composite material provides a feasible solution for high-sensitivity molecular detection and has promising applications in the field of biosensing.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"192 ","pages":"Article 113631"},"PeriodicalIF":4.6,"publicationDate":"2025-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144714179","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}

{"title":"Predicting topological entanglement entropy in a Rydberg analogue simulator","authors":"Linda Mauron, Zakari Denis, Jannes Nys, Giuseppe Carleo","doi":"10.1038/s41567-025-02944-3","DOIUrl":"https://doi.org/10.1038/s41567-025-02944-3","url":null,"abstract":"<p>Predicting the dynamical properties of topological matter is a challenging task, not only in theoretical and experimental settings, but also computationally. Numerical studies are often constrained to studying simplified models and lattices. Here we propose a time-dependent correlated ansatz for the dynamical preparation of a quantum-spin-liquid state on a Rydberg atom simulator. Together with a time-dependent variational Monte Carlo technique, we can faithfully represent the state of the system throughout the entire dynamical preparation protocol. We are able to match not only the physically correct form of the Rydberg atom Hamiltonian but also the relevant lattice topology at system sizes that exceed current experimental capabilities. This approach gives access to global quantities such as the topological entanglement entropy, providing insight into the topological properties of the system. Our results confirm the topological properties of the state during the dynamical preparation protocol, and deepen our understanding of topological entanglement dynamics. We show that, while the simulated state exhibits local properties resembling those of a resonating-valence-bond state, in agreement with experimental observations, it lacks the latter’s characteristic topological entanglement entropy signature irrespective of the degree of adiabaticity of the protocol.</p>","PeriodicalId":19100,"journal":{"name":"Nature Physics","volume":"717 1","pages":""},"PeriodicalIF":19.6,"publicationDate":"2025-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144715338","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}

{"title":"Stepwise Unlock Full‐Spectrum Emission with Abnormal Anti‐Thermal Quenching in Indium‐Based Metal Halides by Tailoring Their Crystal Structure Engineering","authors":"Xiaokang Li, Hui Peng, Ou Xu, Wenjie Huang, Linghang Kong, Qilin Wei, Zhentao Du, Wenchao Yang, Bingsuo Zou","doi":"10.1002/lpor.202501270","DOIUrl":"https://doi.org/10.1002/lpor.202501270","url":null,"abstract":"Lead‐free metal halides with tunable optical properties have emerged as a class of optoelectronic materials with great application potential. The optical properties of metal halides are closely related to their crystal structures, and the diversity of crystal structures is a key factor in achieving efficient tunable emission. Herein, four different Sb<jats:sup>3+</jats:sup>‐doped In<jats:sup>3+</jats:sup>‐based metal halides of 3D Cs<jats:sub>2</jats:sub>KInCl<jats:sub>6</jats:sub>:Sb<jats:sup>3+</jats:sup>, 1D (DFEA)<jats:sub>2</jats:sub>KInCl<jats:sub>6</jats:sub>:Sb<jats:sup>3+</jats:sup> and (DFEA)<jats:sub>2</jats:sub>(NH<jats:sub>4</jats:sub>)InCl<jats:sub>6</jats:sub>:Sb<jats:sup>3+</jats:sup>, and 0D (DFEA)<jats:sub>3</jats:sub>InCl<jats:sub>6</jats:sub>:Sb<jats:sup>3+</jats:sup> (DFEA = 2, 2‐difluoroethylamine) are reported, all of which exhibit different crystal structures, resulting in efficient tunable emission bands shift from 495 to 605 nm. It is found that the larger [SbCl<jats:sub>6</jats:sub>]<jats:sup>3−</jats:sup> distortion is the reason for the redshift of the emission band, which allows to stepwise unlock the full‐spectrum emission with ultra‐high luminescence efficiency. Compared all‐inorganic Cs<jats:sub>2</jats:sub>KInCl<jats:sub>6</jats:sub>:Sb<jats:sup>3+</jats:sup>, the other three Sb<jats:sup>3+</jats:sup>‐doped hybrid In<jats:sup>3+</jats:sup>‐based metal halides exhibit abnormal anti‐thermal quenching behavior, which should be attributed to the participation of shallow trapped states caused by the structural defects. The tunable emission characteristics of Sb<jats:sup>3+</jats:sup>‐doped metal halides make them show great application potential in solid‐state lighting, optical anti‐counterfeiting, and information encryption.","PeriodicalId":204,"journal":{"name":"Laser & Photonics Reviews","volume":"92 1","pages":""},"PeriodicalIF":11.0,"publicationDate":"2025-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144715367","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}

{"title":"A novel labyrinth-type structure enhancing sound insulation properties with acoustic black hole and Herschel-Quincke tube principles","authors":"Jie Jin ,&nbsp;Zhengbin Zhu ,&nbsp;Yunle Cao ,&nbsp;Yecheng Feng ,&nbsp;Haipeng Hao ,&nbsp;Peixin Gao ,&nbsp;Tao Yu","doi":"10.1016/j.apacoust.2025.110972","DOIUrl":"10.1016/j.apacoust.2025.110972","url":null,"abstract":"<div><div>This study proposes a labyrinth-type structure integrating acoustic black hole (ABH) and Herschel-Quincke (HQ) tube principles to achieve noise reduction without compromising ventilation capabilities. The structure directs sound waves toward the ABH outlet through a geometrically tailored profile before channeling them into a labyrinth loop. Locally interconnecting the labyrinth loops forms an HQ tube. To investigate the noise reduction mechanism, a theoretical model was developed using the transfer matrix method, and a numerical simulation was performed via the finite element method. To validate the theoretical and numerical models, a prototype was fabricated with 3D printing technique, and impedance tube experiment was conducted. The results indicate that the ABH enhances the structure’s noise reduction capability, while the HQ tube efficiently attenuates low-frequency noise. Parametric analysis demonstrated that structural modifications-including ABH wall curvature, ABH outlet radius, and HQ tube length-significantly influence noise reduction performance and effective frequency range. Experimental results exhibited excellent agreement with numerical simulation, confirming the design effectiveness. This innovative labyrinth-type structure provides a viable solution for noise control in industrial applications requiring concurrent ventilation and acoustic attenuation.</div></div>","PeriodicalId":55506,"journal":{"name":"Applied Acoustics","volume":"240 ","pages":"Article 110972"},"PeriodicalIF":3.4,"publicationDate":"2025-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144714334","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}

{"title":"Multi-label bird sound recognition based on multi-view learning and dynamic threshold adjustment","authors":"Minghui Fang ,&nbsp;Dengwei Wu ,&nbsp;Wei Wu ,&nbsp;Mengfan Fang ,&nbsp;Yanhong Chen ,&nbsp;Xiangzeng Kong ,&nbsp;Chen Zhao","doi":"10.1016/j.apacoust.2025.110943","DOIUrl":"10.1016/j.apacoust.2025.110943","url":null,"abstract":"<div><div>Bird species monitoring is crucial for conservation, but overlapping vocalizations in natural environments complicate multi-label classification, affecting model performance. To address these issues, we developed the Adaptive Multi-label Attention Threshold Network (AMAT-Net) as a bird sound classification framework. AMAT-Net employs a multi-view strategy, combining bidirectional gated recurrent unit (BiGRU)-attention networks to analyze temporal features and multi-scale convolutional neural networks to extract spectral features, enabling analysis of bird sounds. Given the differences between temporal and spectral features, time-domain features capture transient changes, whereas frequency-domain features reveal spectral trends. Balancing the essential features of both without losing details is difficult. Therefore, we designed the temporal–spectral attention feature fusion (TSAFF) module to optimize feature fusion. TSAFF employs an attention-based mechanism to fuse temporal and spectral features, enhancing the cross-domain feature complementarity. Binary classification is conducted between relevant and irrelevant labels, and threshold is determined based on the results. A score-based thresholding strategy called dynamic threshold scaling was then developed. A label correlation matrix is constructed using Pearson's correlation coefficients, and the classifier's scores for instance-label pairs with high inter-label correlations are adjusted accordingly during prediction. In addition, hierarchical cross-validation is used to search for the threshold that maximizes the F1 score, dynamically optimizing the decision boundary for each species to adapt to the actual label distribution. Experimental results on a synthesized dataset of 10 bird species (including cases of 2, 3, and 4 species vocalizing simultaneously) and the public BirdCLEF+2025 dataset demonstrate that AMAT-Net achieves an accuracy of 95.54% with a macro-F1 score of 91.26% on the synthesized dataset, and an accuracy of 98.75% with a macro-F1 score of 93.14% on BirdCLEF+2025.</div></div>","PeriodicalId":55506,"journal":{"name":"Applied Acoustics","volume":"240 ","pages":"Article 110943"},"PeriodicalIF":3.4,"publicationDate":"2025-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144714335","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}

{"title":"Frequency modulated continuous wave LiDAR with expanded field-of-view based on polarization-splitting metasurface","authors":"Kelan Chen, Jitao Ji, Xueyun Li, Zhiyuan Lin, Zhizhang Wang, Jiacheng Sun, Jian Li, Chunyu Huang, Pan Dai, Jitao Cao, Xiangfei Chen, Shining Zhu, Tao Li","doi":"10.1515/nanoph-2025-0183","DOIUrl":"https://doi.org/10.1515/nanoph-2025-0183","url":null,"abstract":"Frequency modulated continuous wave (FMCW) light detection and ranging (LiDAR) has recently become a research hotspot in the fields of autonomous driving and intelligent perception due to its high-precision ranging and velocity measurement capabilities. However, the existing LiDAR systems are usually challenged in expanding the field-of-view (FOV), which often comes at the expense of beam quality and degrades the detection accuracy and signal-to-noise ratio. On the other hand, the complexity of data processing algorithms may introduce significant measurement inaccuracies, potentially leading to substantial deviations in the final results. These two constraints limit the performance of LiDAR in complex scenarios. To address these issues, this paper proposes a new architecture for FMCW LiDAR that employs a geometric metasurface as a polarization splitter for expanded FOV of beam steering. With the combination of mechanical scanning mirror and metasurface, the scanning FOV has been successfully enlarged from 64° × 20° to 64° × 40°. Simultaneously, millimeter-level precision was achieved in distance measurement, along with an average relative error of 9 mm/s in velocity measurement, which confirms stable and precise system performance. This approach not only broadens the scanning range but also preserves the measurement accuracy of FMCW technology. This paper innovatively combines polarization beam-splitting metasurface with FMCW technology to achieve high-precision measurement over a wide field of view, providing a promising new technical pathway for the technological evolution of future LiDAR systems.","PeriodicalId":19027,"journal":{"name":"Nanophotonics","volume":"12 1","pages":""},"PeriodicalIF":7.5,"publicationDate":"2025-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144715721","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}

{"title":"Synthetic aperture waveguide holography for compact mixed-reality displays with large étendue","authors":"Suyeon Choi, Changwon Jang, Douglas Lanman, Gordon Wetzstein","doi":"10.1038/s41566-025-01718-w","DOIUrl":"https://doi.org/10.1038/s41566-025-01718-w","url":null,"abstract":"<p>Mixed-reality (MR) display systems enable transformative user experiences across various domains, including communication, education, training and entertainment. To create an immersive and accessible experience, the display engine of the MR display must project perceptually realistic 3D images over a wide field of view observable from a large range of possible pupil positions, that is, it must support a large étendue. Current MR displays, however, fall short in delivering these capabilities in a compact device form factor. Here we present an ultra-thin MR display design that overcomes these challenges using a unique combination of waveguide holography and artificial intelligence (AI)-driven holography algorithms. One of the key innovations of our display system is a compact, custom-designed waveguide for holographic near-eye displays that supports a large effective étendue. This is co-designed with an AI-based algorithmic framework combining an implicit large-étendue waveguide model, an efficient wave propagation model for partially coherent mutual intensity and a computer-generated holography framework. Together, our unique co-design of a waveguide holography system and AI-driven holographic algorithms represents an important advancement in creating visually comfortable and perceptually realistic 3D MR experiences in a compact wearable device.</p>","PeriodicalId":18926,"journal":{"name":"Nature Photonics","volume":"63 1","pages":""},"PeriodicalIF":35.0,"publicationDate":"2025-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144715276","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}

{"title":"Experimental analysis of the thermal management and internal quantum efficiency of terahertz quantum cascade laser harmonic frequency combs","authors":"M. Alejandro Justo Guerrero, Elisa Riccardi, Lianhe Li, Mark Rosamond, A. Giles Davies, Edmund H. Linfield, Miriam S. Vitiello","doi":"10.1515/nanoph-2025-0207","DOIUrl":"https://doi.org/10.1515/nanoph-2025-0207","url":null,"abstract":"Quantum cascade laser (QCL) harmonic state frequency combs (HFCs) have recently attracted considerable interest for applications ranging from the generation of tones of high spectral purity, high data rate wireless communication networks, radiofrequency arbitrary waveform synthesis, and for fundamental light-matter investigations in quantum physics. However, a detailed knowledge of the nature of the electronic and thermal energy distribution in these devices is of paramount importance for the refinement of their thermal management and quantum efficiency, which are key to the widespread adoption of QCL HFC technology in a new generation of integrated optical quantum platforms. Here, we perform a comparative study of the thermal and electronic properties of Fabry–Perot and micro-ring HFC QCLs, operating in the terahertz frequency range, using micro-probe band-to-band photoluminescence. By monitoring the lattice temperature and the electron cooling above the threshold for stimulated emission, we extract the device thermal resistances and the internal quantum efficiencies, highlighting the key role of the resonator architecture.","PeriodicalId":19027,"journal":{"name":"Nanophotonics","volume":"63 1","pages":""},"PeriodicalIF":7.5,"publicationDate":"2025-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144715717","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}

{"title":"Spin–lattice coupling and anisotropic magneto-transport in Fe-ordered Fe5−xGeTe2","authors":"Junbo Li, Yihao Wang, Peng Wu, Jiangpeng Song, Zhihao Li, Liang Cao, Guopeng Wang, Yimin Xiong","doi":"10.1063/5.0266796","DOIUrl":"https://doi.org/10.1063/5.0266796","url":null,"abstract":"Two-dimensional van der Waals (vdW) magnetic materials have attracted extensive attention for the development of next-generation spintronic devices. The vdW magnet Fe5−xGeTe2 exhibits reversible spin structure and distinct electronic band structures tuned by thermal process with the Curie temperature (TC) above room temperature. By using a quench process, Fe5−xGeTe2 shows Fe(1) sites ordered in the crystal structure and nontrivial flatbands in electronic structures. However, detailed experimental investigations of physical properties in the Fe-ordered phase remain limited. In this work, we synthesize the Fe-ordered Fe5−xGeTe2 crystals and systematically investigate the physical properties by the combination of multiple measurements. The enhanced electronic specific heat coefficient (γ = 70.43 mJ mol−1 K−2) and Kadowaki–Woods ratio (A/γ2≈ 2.6 μΩ cm mol2 K2 J−2) provide evidence for the existence of flatbands and strong electron correlations. Furthermore, strong spin–lattice coupling is observed, where magnetic phase transitions coincide with lattice vibrations and Raman spectral shifts. In addition, anisotropic magneto-transport properties reveal the coupling between Fe(1) magnetic moments and charge carriers in the ordered phase. Our results provide further experimental evidence of the flatbands in the Fe-ordered phase as well as offer a strategy for designing tunable spintronic devices by exploiting the synergy between spin and lattice dynamics in vdW heterostructures.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"708 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144715722","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}

{"title":"Measuring black hole spin through gravitational lensing of pulsars","authors":"Amjad Ashoorioon, Mohammad Bagher Jahani Poshteh and Robert B Mann","doi":"10.1088/1361-6382/adef8d","DOIUrl":"https://doi.org/10.1088/1361-6382/adef8d","url":null,"abstract":"We propose a new procedure for measuring the spin of a black hole with an unprecedented accuracy based on the gravitational lensing of millisecond pulsars. We derive the basic equations for lensing by a rotating black hole. We show that the frame dragging effect increases the deflection angle of a light ray co-rotating with the black hole. For the primary (secondary) images the angular positions are larger (smaller) for a rotating black hole by an amount on the order of tens of microarcseconds. The differential time delay of images for the case in which the lens is a rotating black hole is smaller than that in the case of non-rotating lens of the same mass, and it can be larger than a few milliseconds. We show that this quantity offers the possibility of reducing the error of spin measurement to less than one percent if we could measure the differential time delay with accuracy of microseconds. We also study relativistic images that are produced by light rays that rotate around the black hole before reaching the observer. The angular positions of relativistic images on the same side as the primary (secondary) image are a few microarcseconds larger (smaller) if the black hole is rotating. Furthermore, the differential time delay between relativistic images is about twelve orders of magnitude larger in the case of rotating lens.","PeriodicalId":10282,"journal":{"name":"Classical and Quantum Gravity","volume":"22 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144715335","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}