物理与天体物理最新文献

{"title":"Micro-tip manipulated origami for robust twisted few-layer graphene","authors":"Ruo-Jue Zou, Long Deng, Si-Min Xue, Feng-Fei Cai, Ling-Hui Tong, Yang Zhang, Yuan Tian, Li Zhang, Lijie Zhang, Zhihui Qin, Long-Jing Yin","doi":"10.1063/5.0265918","DOIUrl":"https://doi.org/10.1063/5.0265918","url":null,"abstract":"Twisted few-layer graphene (tFLG) has emerged as an ideal model system for investigating novel strongly correlated and topological phenomena. However, the experimental construction of tFLG with high structural stability is still challenging. Here, we introduce a highly accessible method for fabricating robust tFLG by polymer micro-tip manipulated origami. Through using a self-prepared polymer micro-tip—which is composed of multiple dimethylpolysiloxane, poly(vinyl chloride), and graphite sheets—to fold graphene layers, we fabricated tFLG with different twist angles (0°–30°) and various layers, including twisted bilayers (1 + 1), twisted double-bilayers (2 + 2), twisted double-trilayers (3 + 3), and thicker layers. Even ABC-stacked tFLG were created, such as twisted ABC/ABC and ABC/ABA graphene coexisting in an ABC-ABA domain wall region. We found that the origami-fabricated tFLG exhibits high stability against thermal and mechanical perturbations including heating and transferring, which could be attributed to its special folding and tearing structures. Moreover, based on the rich types of samples, we revealed twist-angle- and stacking-order-dependent Raman characteristics of tFLG, which are valuable for understanding stacking-modulated phonon spectroscopy. Our experiments provide a simple and efficient approach to construct structurally robust tFLG, paving the way for the study of highly stable twisted van der Waals heterostructures.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"44 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143876367","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":"Corrugation-Dominated Mechanical Softening of Defect-Engineered Graphene","authors":"Wael Joudi, Rika Saskia Windisch, Alberto Trentino, Diana Propst, Jacob Madsen, Toma Susi, Clemens Mangler, Kimmo Mustonen, Florian Libisch, Jani Kotakoski","doi":"10.1103/physrevlett.134.166102","DOIUrl":"https://doi.org/10.1103/physrevlett.134.166102","url":null,"abstract":"We measure the two-dimensional elastic modulus E</a:mi></a:mrow>2</a:mn>D</a:mi></a:mrow></a:msup></a:mrow></a:math> of atomically clean defect-engineered graphene with a known vacancy distribution and density in correlated ultrahigh vacuum experiments. The vacancies are introduced via low-energy (<d:math xmlns:d=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><d:mrow><d:mo>&lt;</d:mo><d:mn>200</d:mn><d:mtext> </d:mtext><d:mtext> </d:mtext><d:mi>eV</d:mi></d:mrow></d:math>) Ar ion irradiation, and the atomic structure is obtained via semiautonomous scanning transmission electron microscopy and image analysis. Based on atomic force microscopy nanoindentation measurements, a decrease of <f:math xmlns:f=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><f:msup><f:mi>E</f:mi><f:mrow><f:mn>2</f:mn><f:mi mathvariant=\"normal\">D</f:mi></f:mrow></f:msup></f:math> from 286 to <i:math xmlns:i=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><i:mrow><i:mn>158</i:mn><i:mtext> </i:mtext><i:mtext> </i:mtext><i:mi mathvariant=\"normal\">N</i:mi><i:mo>/</i:mo><i:mi mathvariant=\"normal\">m</i:mi></i:mrow></i:math> is observed when measuring the same graphene membrane before and after introducing vacancies at a density of <m:math xmlns:m=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><m:mrow><m:mn>1.0</m:mn><m:mo>×</m:mo><m:msup><m:mrow><m:mn>10</m:mn></m:mrow><m:mrow><m:mn>13</m:mn></m:mrow></m:msup><m:mtext> </m:mtext><m:mtext> </m:mtext><m:mrow><m:msup><m:mrow><m:mi>cm</m:mi></m:mrow><m:mrow><m:mo>−</m:mo><m:mn>2</m:mn></m:mrow></m:msup></m:mrow></m:mrow></m:math>. This decrease is significantly greater than what is predicted by most theoretical studies and in stark contrast to some measurements presented in the literature. With the assistance of atomistic simulations, we show that this softening is mostly due to corrugations caused by local strain at vacancies with two or more missing atoms, while the influence of single vacancies is negligible. We further demonstrate that the opposite effect can be measured when surface contamination is not removed before defect engineering. <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":"91 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143875954","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":"Equivalence of two constructions for (widehat{sl}_2)-integrable hierarchies","authors":"Panpan Dang,&nbsp;Yajuan Li,&nbsp;Yuanyuan Zhang,&nbsp;Jipeng Cheng","doi":"10.1134/S0040577925040063","DOIUrl":"10.1134/S0040577925040063","url":null,"abstract":"<p> We discuss the equivalence between the Date–Jimbo–Kashiwara–Miwa (DJKM) construction and the Kac–Wakimoto (KW) construction of <span>(widehat{sl}_2)</span>-integrable hierarchies within the framework of bilinear equations. The DJKM method has achieved remarkable success in constructing integrable hierarchies associated with classical A, B, C, D affine Lie algebras. In contrast, the KW method exhibits broader applicability, as it can be employed even for exceptional E, F, G affine Lie algebras. However, a significant drawback of the KW construction lies in the great difficulty of obtaining Lax equations for the corresponding integrable hierarchies. Conversely, in the DJKM construction, Lax structures for numerous integrable hierarchies can be derived. The derivation of Lax equations from bilinear equations in the KW construction remains an open problem. Consequently, demonstrating the equivalent DJKM construction for the integrable hierarchies obtained via the KW construction would be highly beneficial for obtaining the corresponding Lax structures. In this paper, we use the language of lattice vertex algebras to establish the equivalence between the DJKM and KW methods in the <span>(widehat{sl}_2)</span>-integrable hierarchy for principal and homogeneous representations. </p>","PeriodicalId":797,"journal":{"name":"Theoretical and Mathematical Physics","volume":"223 1","pages":"597 - 623"},"PeriodicalIF":1.0,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143875283","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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":"Linear representations of the Lie algebra of the diffeomorphism group in (mathbb{R}^d)","authors":"M. I. Gozman","doi":"10.1134/S0040577925040014","DOIUrl":"10.1134/S0040577925040014","url":null,"abstract":"<p> A family of representations of the Lie algebra of the diffeomorphism group in <span>(mathbb{R}^d)</span> is studied. A method for constructing representations of this family is proposed. Equations for matrices describing the action of the Lie algebra on the representation space are obtained. It is shown that the developed formalism is suitable for describing representations under which fields of linear homogeneous geometric objects are transformed. The formalism is shown to allow describing representations for which the representation space vectors cannot be expressed in terms of fields of linear homogeneous geometric objects. An example of such a representation is studied. </p>","PeriodicalId":797,"journal":{"name":"Theoretical and Mathematical Physics","volume":"223 1","pages":"525 - 547"},"PeriodicalIF":1.0,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143875286","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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":"Photoelectron Spin Texture in Tunneling Ionization Induced by a Linearly Polarized Laser Pulse","authors":"Pei-Lun He, Zhao-Han Zhang, Karen Z. Hatsagortsyan, Christoph H. Keitel","doi":"10.1103/physrevlett.134.163201","DOIUrl":"https://doi.org/10.1103/physrevlett.134.163201","url":null,"abstract":"The spin polarization of photoelectrons in tunneling ionization is investigated using numerical solutions of the time-dependent Schrödinger equation in companion with our analytic treatment via the spin-resolved strong-field approximation and classical trajectory Monte Carlo simulations. We demonstrate a nontrivial spin texture of photoelectrons in momentum space, exhibiting a vortex structure relative to the laser polarization axis. The momentum-resolved polarization stems from the emergence of spin-correlated quantum orbits in the continuum. For direct electrons in few-cycle pulses, the nonvanishing initial transverse velocity of the electron is responsible for the polarization, while in long pulses, the spin texture is essentially shaped by recollisions. Furthermore, the interference between direct and rescattering ionization leads to spin-polarized electron holography, offering an alternative method to extract atomic fine structural information. <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":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143876019","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":"Robust Nodal Behavior in the Thermal Conductivity of Superconducting UTe2","authors":"Ian M. Hayes, Tristin E. Metz, Corey E. Frank, Shanta R. Saha, Nicholas P. Butch, Vivek Mishra, P. J. Hirschfeld, Johnpierre Paglione","doi":"10.1103/physrevx.15.021029","DOIUrl":"https://doi.org/10.1103/physrevx.15.021029","url":null,"abstract":"The superconducting state of the heavy-fermion metal UTe</a:mi></a:mrow>2</a:mn></a:mrow></a:msub></a:mrow></a:math> has attracted considerable interest because of evidence of spin-triplet Cooper pairing and nontrivial topology. Progress on these questions requires identifying the presence or absence of nodes in the superconducting gap function and their dimension. In this article, we report a comprehensive study of the influence of disorder on the thermal transport in the superconducting state of <c:math xmlns:c=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><c:mrow><c:msub><c:mrow><c:mi>UTe</c:mi></c:mrow><c:mrow><c:mn>2</c:mn></c:mrow></c:msub></c:mrow></c:math>. Through detailed measurements of the magnetic-field dependence of the thermal conductivity in the zero-temperature limit, we obtain clear evidence of the presence of point nodes in the superconducting gap for all samples with transition temperatures ranging from 1.6 to 2.1 K obtained by different synthesis methods, including a refined self-flux method. This robustness implies the presence of symmetry-imposed nodes throughout the range studied, further confirmed via disorder-dependent calculations of the thermal transport in a model with a single pair of nodes. In addition to capturing the temperature dependence of the thermal conductivity up to <e:math xmlns:e=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><e:msub><e:mi>T</e:mi><e:mi>c</e:mi></e:msub></e:math>, this model provides some information about the locations of the nodes, suggesting a <g:math xmlns:g=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><g:msub><g:mi>B</g:mi><g:mrow><g:mn>1</g:mn><g:mi>u</g:mi></g:mrow></g:msub></g:math> or <i:math xmlns:i=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><i:msub><i:mi>B</i:mi><i:mrow><i:mn>2</i:mn><i:mi>u</i:mi></i:mrow></i:msub></i:math> symmetry for the superconducting order parameter. Additionally, comparing the new, ultrahigh conductivity samples to older samples reveals a crossover between a low-field and a high-field regime at a single value of the magnetic field in all samples. In the high-field regime, the thermal conductivity at different disorder levels differs from each other by a simple offset, suggesting that some simple principle determines the physics of the mixed state, a fact which may illuminate trends observed in other clean nodal superconductors. <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":20161,"journal":{"name":"Physical Review X","volume":"24 1","pages":""},"PeriodicalIF":12.5,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143876068","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":"Optical chaotic secure bidirectional communication based on optical injected electro-optical phase delay feedback loop","authors":"Fei Wang, Xuefang Zhou, Yuming Zhang, Jie Luo","doi":"10.1007/s10043-025-00972-1","DOIUrl":"https://doi.org/10.1007/s10043-025-00972-1","url":null,"abstract":"<p>To enhance chaotic complexity and conceal time-delay signatures, we propose an optically chaotic secure communication system. The system combines chaotic intensity signals from an amplified spontaneous emission (ASE) noise source with an electro-optical phase delay oscillating feedback loop through optical injection. It integrates all-optical intensity chaos and electro-optical feedback to produce complex chaotic signals. ASE noise acts as an entropy source, while a fiber Bragg grating (FBG) enhances signal complexity by leveraging its dispersion properties. This approach significantly expands the system’s key space. The transmitted information is nonlinearly coupled with the chaotic carrier via phase modulation, contributing to the chaotic carrier’s generation. At the receiver, optical chaotic synchronization decrypts the transmitted signals. Performance analysis shows that the system effectively hides time-delay signatures, increases chaotic complexity, and exhibits strong resistance to parameter mismatches. These results demonstrate its high security for physical-layer communication.</p>","PeriodicalId":722,"journal":{"name":"Optical Review","volume":"42 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143873012","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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":"Computations of eclipses from 14th-century manuscript Ekanāthakaraṇa","authors":"B. S. SHYLAJA,&nbsp;B. S. SHUBHA","doi":"10.1007/s12036-025-10045-z","DOIUrl":"10.1007/s12036-025-10045-z","url":null,"abstract":"<div><p>The procedures followed for computations of eclipses in the classical treatises are best understood with a practical demonstration of the technique. Here, we have studied manuscripts describing the computations. These are authored by <i>Ekanātha</i> of the 14th century, whose works are not well known. We demonstrate the procedure by practical verification of each step and finally comparing the results with currently available computations. In the process, the finer details of valuable tools, like the iteration method, are brought to light. The drawings of the eclipses are presented as per the procedure. The possible causes for the observed discrepancies in the results are discussed. </p></div>","PeriodicalId":610,"journal":{"name":"Journal of Astrophysics and Astronomy","volume":"46 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143871406","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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":"Microlenses on photonic integrated circuits enable flexible packaging and optical isolator integration","authors":"Jeroen Missinne,&nbsp;Rik Verplancke,&nbsp;Yao-Tung Chang ,&nbsp;Geert Van Steenberge","doi":"10.1016/j.optlastec.2025.112940","DOIUrl":"10.1016/j.optlastec.2025.112940","url":null,"abstract":"<div><div>This paper presents a versatile microlens integration platform designed to address key packaging challenges in photonic integrated circuits (PICs), particularly in enhancing coupling efficiency, increasing working distance, and enabling the hybrid integration of external optical components, such as isolators, which are difficult to integrate monolithically. We first describe multiple integration strategies for microlenses with PICs toward achieving relaxed alignment tolerances and extended working distances when interfacing with fiber arrays. To demonstrate the platform’s possibilities, we detail two specific use cases. The first involves a long working distance expanded beam interface for O-band datacom applications, where a microlensed PIC, paired with a microlensed connector, achieves a 3.8<!--> <!-->mm working distance with a modest additional insertion loss of 0.85<!--> <!-->dB per interface attributed to integration of the lenses. This configuration offers improved lateral and longitudinal alignment tolerances, making it well-suited for pluggable connector applications. The second use case demonstrates the integration of an optical isolator within the coupling interface of a C-band PIC, achieving an isolator insertion loss of 1.2<!--> <!-->dB and a broad 1<!--> <!-->dB bandwidth of 80<!--> <!-->nm, with an extinction ratio of -20<!--> <!-->dB at the target 1540<!--> <!-->nm wavelength. Together, these use cases highlight the potential of microlens-based solutions to address PIC packaging requirements, offering enhanced tolerance management and enabling new possibilities for hybrid integration of complex optical functionalities.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"189 ","pages":"Article 112940"},"PeriodicalIF":4.6,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143868611","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":"Tm fiber laser in-band pumped Ho:YLF/SrWO4 intracavity mid-infrared Raman laser at 2550 nm","authors":"Xiaofan Jing,&nbsp;Xinlu Zhang,&nbsp;Changchang Shen,&nbsp;Jinjer Huang","doi":"10.1016/j.optlastec.2025.113033","DOIUrl":"10.1016/j.optlastec.2025.113033","url":null,"abstract":"<div><div>We first report on the 2550 nm mid-infrared acousto-optic Q-switched Ho:YLF/SrWO₄ intracavity Raman laser in-band pumped by a 1940 nm Tm fiber laser. The output performances of Ho:YLF/SrWO₄ Raman laser were investigated at several different pulse repetition frequencies. Based on the stimulated Raman scattering effect, the 2065 nm fundamental laser was converted to the 2550 nm Raman laser. At the pulse repetition frequency of 4 kHz, the maximum average output power of 900 mW was achieved with a pulse width of 17.07 ns. The corresponding single pulse energy and peak power were 225 μJ and 13.18 kW, respectively.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"189 ","pages":"Article 113033"},"PeriodicalIF":4.6,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143868612","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}