物理与天体物理最新文献

{"title":"Practical Framework for Analyzing High-Dimensional Quantum Key Distribution Setups","authors":"Florian Kanitschar, Marcus Huber","doi":"10.1103/physrevlett.135.010802","DOIUrl":"https://doi.org/10.1103/physrevlett.135.010802","url":null,"abstract":"High-dimensional (HD) entanglement promises both enhanced key rates and overcoming obstacles faced by modern-day quantum communication. However, modern convex optimization-based security arguments are limited by computational constraints; thus, accessible dimensions are far exceeded by progress in HD photonics, bringing forth a need for efficient methods to compute key rates for large encoding dimensions. In response to this problem, we present a flexible analytic framework facilitated by the dual of a semidefinite program and diagonalizing operators inspired by entanglement-witness theory, enabling the efficient computation of key rates in high-dimensional systems. To facilitate the latter, we show how matrix completion techniques can be incorporated to effectively yield improved, computable bounds on the key rate in paradigmatic high-dimensional systems of time- or frequency-bin entangled photons and beyond, revealing the potential for very high-dimensions to surpass low dimensional protocols already with existing technology. In our accompanying work, (F. Kanitschar and M. Huber, Composable finite-size security of high-dimensional quantum key distribution protocols), available on arXiv, we show how our findings can be used to establish finite-size security against coherent attacks for general HD-QKD protocols both in the fixed- and variable-length scenario. <jats:supplementary-material> <jats:copyright-statement>Published by the American Physical Society</jats:copyright-statement> <jats:copyright-year>2025</jats:copyright-year> </jats:permissions> </jats:supplementary-material>","PeriodicalId":20069,"journal":{"name":"Physical review letters","volume":"27 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144533201","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":"From bubble dynamics to acoustic control: Underwater bubble-based metamaterials for marine sustainability","authors":"Qibo Deng, Tianying Du, Cuihua An, Zhandong Huang","doi":"10.1063/5.0256788","DOIUrl":"https://doi.org/10.1063/5.0256788","url":null,"abstract":"Marine acoustics is crucial for the sustainable utilization of ocean resources. Researchers have discovered that underwater bubbles can serve as highly efficient acoustic resonators, enabling precise manipulation of sound waves in water. However, understanding the complex dynamics of bubble evolution in fluids is essential to optimize their acoustic characteristics. This review provides theoretical forecasts and practical approaches for studying bubble evolution, along with an overview of recent advancements in underwater bubble metamaterials. It covers classical and modified theoretical equations and explores strategies for modifying acoustic environments through resonant coupling in bubbles. Techniques, such as applying external forces, introducing surfactants, and creating micropatterned designs for structuring bubbles, are discussed. This review evaluates the superior acoustic properties of underwater bubble metamaterials, including their reflection, absorption, and transmission capabilities and their potential applications in marine environments. Finally, this study outlines the challenges that need to be addressed to manage bubble dynamics and enhance acoustic metamaterial technologies for underwater applications. These insights are expected to contribute to the sustainable development of the ocean.","PeriodicalId":8200,"journal":{"name":"Applied physics reviews","volume":"652 1","pages":""},"PeriodicalIF":15.0,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144533255","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":"Time series forecasting of train axle fatigue crack acoustic emission signals by integrating multi-head attention mechanism into DLinear model","authors":"Li Lin,&nbsp;Xiaonan Shang","doi":"10.1016/j.apacoust.2025.110922","DOIUrl":"10.1016/j.apacoust.2025.110922","url":null,"abstract":"<div><div>Among the many factors affecting train safety, the health of train axles is particularly critical. As an important part of the train, cracks in the axle can lead to serious safety accidents if not detected and treated in a timely manner. Acoustic emission technology can detect cracks at an early stage and, as an online real-time detection method, is essential to ensure the reliability of axles. This technology not only improves the timeliness of fault detection but also provides strong support for train maintenance and management. However, obtaining complete and continuous crack extension data is challenging due to environmental and equipment limitations. Therefore, real-time prediction of crack development during train operation has become particularly important. The real-time prediction of the sequence of acoustic emission signals enables the early detection of potential faults, thus effectively preventing the occurrence of major accidents. Therefore, we propose an improved model based on DLinear, designed for real-time prediction of acoustic emission signal time series. This model innovatively incorporates a multi-head attention mechanism into both the trend and seasonal branches. This unique architectural design enables the trend branch to more accurately capture nonlinear variation features while significantly enhancing the seasonal branch’s ability to analyze high-frequency fluctuating signals. Experimental results demonstrate that our proposed algorithm can effectively predict the time series of acoustic emission signals from fatigue cracks in axles.</div></div>","PeriodicalId":55506,"journal":{"name":"Applied Acoustics","volume":"240 ","pages":"Article 110922"},"PeriodicalIF":3.4,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144523502","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":"Gallium nitride: a strong candidate to replace GaAs as base material for optical photovoltaic converters in space exploration","authors":"Javier F. Lozano ,&nbsp;Natalia Seoane ,&nbsp;J.M. Guedes ,&nbsp;Enrique Comesaña ,&nbsp;Julian G. Fernandez ,&nbsp;Florencia M. Almonacid ,&nbsp;Eduardo F. Fernández ,&nbsp;Antonio García-Loureiro","doi":"10.1016/j.optlastec.2025.113447","DOIUrl":"10.1016/j.optlastec.2025.113447","url":null,"abstract":"<div><div>High power laser transmission technology is expected to play an important role in spatial exploration. To increase the amount of power delivered, some issues must be addressed. Currently, optical photovoltaic converters are based on GaAs, a material with a bandgap energy of 1.42 eV. In this work we propose gallium nitride (GaN) as base material for optical photovoltaic converters due to its high bandgap (3.39 eV), which reduces both ohmic and intrinsic entropic losses, and its high thermal conductivity and resistance to radiation damage, making it suitable for space applications. We have optimized several GaN optical photovoltaic converter devices under a wide range of laser power densities and temperatures. The resilience to variations in the design parameters is also tested. Results show that, due to their large bandgap energy, GaN devices could suffer from fewer performance losses with the temperature when compared to other materials with lower bandgaps. The devices show great tolerance to variations in the P layer (bottom layer), while the N layer thickness and doping concentration must be carefully manufactured. When compared to GaAs-based devices, GaN shows higher efficiency across the entire laser power density range, achieving efficiencies near 80 % and surpassing the current state-of-the-art power converter by <span><math><mo>≈</mo></math></span>10 % at 10 <span><math><mtext>W</mtext><mspace></mspace><msup><mtext>cm</mtext><mrow><mo>−</mo><mn>2</mn></mrow></msup></math></span>. The proposed GaN devices show a peak of performance at a laser power density as high as 100 <span><math><mtext>W</mtext><mspace></mspace><msup><mtext>cm</mtext><mrow><mo>−</mo><mn>2</mn></mrow></msup></math></span>. Although manufacturing issues could degrade the efficiency of GaN power converters, this results position GaN as a promising material for a new generation of ultra-high efficient optical photovoltaic converters.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"192 ","pages":"Article 113447"},"PeriodicalIF":4.6,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144523391","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":"Van der Waals epitaxy of GeSn quantum dots on MoS2 enabled by oxygen-plasma pretreatment","authors":"Xiaowei Shentu, Rui Wang, Weinan Zheng, Chengyuan Yang, Haokun Ding, Songsong Wu, Jinhui Qian, Guangyang Lin, Songyan Chen, Wei Huang, Cheng Li","doi":"10.1063/5.0269760","DOIUrl":"https://doi.org/10.1063/5.0269760","url":null,"abstract":"GeSn quantum dots (QDs) have garnered much attention as a candidate for monolithically optoelectronic integration due to its direct bandgap and full compatibility with CMOS technology. However, it is still a big challenge to make GeSn QDs because of the low solubility of Sn in Ge and too thick coherently strained GeSn layer grown on Ge or Si substrates at low temperature. In this Letter, van der Waals epitaxy of GeSn QDs with high Sn content of 9.2% on oxygen-plasma modified two-dimensional MoS2 on SiO2/Si substrate is demonstrated using magnetron sputtering. The growth kinetics is proposed, in which oxygen-plasma modification introduces sulfur vacancies on the MoS2 surface, mediating an Sn wetting layer to promote Ge nucleation to form GeSn QDs. The transitions between GeSn QDs and thin films and the precise control over quantum dot density and morphology are performed by simply tuning the sputtering power and durations. As a result, GeSn QDs with high aspect ratio of 1.2 are achieved with excellent crystalline quality. This work provides an intriguing way to construct GeSn QDs on 2D materials for optoelectronic device applications.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"19 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144533171","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":"High-power 2.2 THz quantum-cascade laser with sixth-order distributed feedback","authors":"Fei Jia, Sadhvikas J. Addamane, John L. Reno, Sushil Kumar","doi":"10.1063/5.0273563","DOIUrl":"https://doi.org/10.1063/5.0273563","url":null,"abstract":"A distributed-feedback (DFB) scheme with sixth-order Bragg gratings realizes high-power emission for low-frequency single-mode terahertz quantum-cascade lasers (QCLs). The gratings are implemented in top claddings of plasmonic metallic cavities of the QCLs with four appropriately placed radiating slits per period. A peak optical power of 112 mW is detected for a 2.2 THz surface-emitting QCL in a single-lobed beam at 59 K, with a maximum operating temperature of 97 K in pulsed-mode. Numerical modeling indicates that the DFB scheme allows for a large variation of the radiative loss by adjusting the slits, and hence may be suitable for different types of QCL active regions.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"2 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144533174","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":"Modulation of charge transport and rectification behavior in CsSnI3 thin films through A-site cation engineering","authors":"Anna A. Zarudnyaya, Gleb V. Segal, Andrey P. Morozov, Lev O. Luchnikov, Sergey Yu. Yurchuk, Alexey E. Aleksandrov, Ildar R. Sayarov, Alexey R. Tameev, Oleg Rabinovich, Ivan V. Schemerov, Pavel A. Gostishchev, Danila S. Saranin","doi":"10.1063/5.0272415","DOIUrl":"https://doi.org/10.1063/5.0272415","url":null,"abstract":"CsSnI3 perovskite is a thin-film semiconductor with high intrinsic conductivity for various device applications (thermoelectric, photovoltaics, etc.). Stoichiometric CsSnI3 has high-density defects and structural imperfections affecting device performance. In this work, we made an investigation on A-site cation engineering to evaluate the correlation between structural and transport parameters for effective operation in rectifying devices. Here, we analyzed CsSnI3 thin films modified with methylamine (MA), formamidine (FA), guanidine (GuA), and 5-ammonium valeric acid (AVA) cations, correlating structural parameters obtained by Rietveld refinement with their optoelectronic and diode characteristics. MA-, FA-, and GuA-substituted films exhibited low sheet resistance (∼450–2200 Ω/sq); however, strain-induced lattice distortions and accumulated defects in GuA-substituted films significantly hindered effective charge collection and increased recombination losses. AVA substitution formed low-conductivity 2D interlayers, increasing resistance (&amp;gt;105 Ω/sq) and altering transient response characteristics, yet provided minimal reverse switching losses (∼100 μW/cm2), beneficial for high-frequency applications. FA substitution emerged as optimal, balancing structural stability, conductivity, minimal defects, and relevant diode properties. The obtained results highlight that targeted lattice modifications strongly influence the practical performance of rectifying p–i–n diodes based on CsSnI3.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"65 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144533209","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":"Developments for quantum inertial navigation systems employing Bose–Einstein condensates","authors":"M. Gersemann, A. Rajagopalan, M. Abidi, P. Barbey, A. Sabu, X. Chen, N. B. Weddig, B. Tennstedt, J. Petring, N. Droese, A. Kassner, C. Künzler, L. Keinert, X. Xiao, F. Dencker, M. C. Wurz, A. Löwer, E. von Hinüber, D. Schlippert, E. M. Rasel, S. Schön, S. Abend","doi":"10.1063/5.0250666","DOIUrl":"https://doi.org/10.1063/5.0250666","url":null,"abstract":"Quantum technology became a new tool for navigation based on measuring accelerations and rotations. However, the full potential of atom interferometers that operate with ultracold atoms has not yet been exploited. This paper presents current developments in the field of generation and application of Bose–Einstein condensates for inertial navigation. It covers the advancements in the form of atom chip and compact vacuum technology, classical sensor hybridization, and a multi-axis atom interferometry technique. In addition, the synergies of combining quantum sensors with classical inertial measurement units and their implications for navigation trajectories are discussed.","PeriodicalId":8200,"journal":{"name":"Applied physics reviews","volume":"2 1","pages":""},"PeriodicalIF":15.0,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144533215","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":"On-chip deterministic arbitrary-phase-controlling","authors":"Rui Ma, Chu Li, Qiuchen Yan, Xinyi Wang, Ruiqi Wang, Yufei Wang, Yumeng Chen, Yan Li, Cuicui Lu, Jianwei Wang, Xiaoyong Hu, Che Ting Chan, Qihuang Gong","doi":"10.1515/nanoph-2025-0132","DOIUrl":"https://doi.org/10.1515/nanoph-2025-0132","url":null,"abstract":"The stable on-chip deterministic arbitrary-phase-controlling of signal light in micro/nanometer spatial scale is an extremely important basis for large-scale and high-density integrated photonic information processing chips. Conventional phase-controlling methods face with serious limitation of unavoidable crosstalk, length distortion, and fabrication error. To date, it is still a great challenge to achieve deterministic and wide-range on-chip arbitrary-phase-controlling. Here, we report an effective strategy of three-waveguide coupled configuration to realize on-chip deterministic arbitrary-phase-controlling (ranging from 0 to 2<jats:italic>π</jats:italic>) by combing the dynamic phase and the geometric phase. Based on this strategy, quantum gate operations in an optical permutation-group circuit are successfully realized in femtosecond-laser direct writing sample. To extend the feasibility of this method, on-chip silicon-based deterministic arbitrary-phase-controlling in the optical communication range is also experimentally verified. Our work not only paves the way for fundamental research in chip-scale novel optical devices but also promotes the study of topological quantum computing.","PeriodicalId":19027,"journal":{"name":"Nanophotonics","volume":"13 1","pages":""},"PeriodicalIF":7.5,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144533268","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":"Broadband and Polarization‐Multiplexed Nonreciprocal Transmission Enabled by Magneto‐Optical Metasurface","authors":"Guoqin Cao, Yue Wang, Chunsheng Guan, Jiahui Fu, Cong Wang, Xumin Ding","doi":"10.1002/lpor.202500559","DOIUrl":"https://doi.org/10.1002/lpor.202500559","url":null,"abstract":"The violation of Lorentz reciprocity through directional electromagnetic transmission constitutes a cornerstone for advancing next‐generation photonic architectures. While existing implementations predominantly exhibit nonreciprocal behavior limited to individual polarization bases with inherently constrained bandwidth. Here, a magneto‐optical nonreciprocal metasurface (NRM) is proposed to achieve concurrent polarization‐multiplexed functionalities: polarization‐dependent nonreciprocity for circularly polarized waves and unidirectional transmission for linear polarization. This dual functionality originates from coordinated spatiotemporal symmetry breaking across orthogonal electromagnetic eigenstates, enabling independent wavefront manipulation through tailored bi‐anisotropic responses. The proposed magneto‐optical metasurface comprises a thin layer of Yttrium Iron Garnet (YIG) integrated with a Magnesium‐Titanium Dielectric Ceramics resonator (MTDCR) rotated by 30° along the <jats:italic>z</jats:italic>‐axis. The nonreciprocal transmission effect arises from the simultaneous breaking of two distinct symmetries: gyroscopic mirror symmetry and time‐reversal symmetry. Furthermore, the magneto‐electric coupling between Mie resonances excited within the MTDCR and Fabry‐Pérot modes sustained in the subwavelength YIG layer establishes a spectral broadening mechanism, achieving a record relative bandwidth of 12% across operational spectra. The NRM exhibits exceptional performance with 94% transmittance and maintains nonreciprocal functionality for incident angles up to 50°. This work establishes a universal platform for developing nonreciprocal photonic systems with applications in quantum communications and 6G full‐duplex radar.","PeriodicalId":204,"journal":{"name":"Laser & Photonics Reviews","volume":"47 1","pages":""},"PeriodicalIF":11.0,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144533220","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}