物理与天体物理最新文献

{"title":"An Experimental Platform for Studying the Heteronuclear Efimov Effect with an Ultracold Mixture of (^textbf{6})Li and (^textbf{133})Cs Atoms","authors":"Eleonora Lippi,&nbsp;Manuel Gerken,&nbsp;Stephan Häfner,&nbsp;Marc Repp,&nbsp;Rico Pires,&nbsp;Michael Rautenberg,&nbsp;Tobias Krom,&nbsp;Eva D. Kuhnle,&nbsp;Binh Tran,&nbsp;Juris Ulmanis,&nbsp;Bing Zhu,&nbsp;Lauriane Chomaz,&nbsp;Matthias Weidemüller","doi":"10.1007/s00601-024-01971-9","DOIUrl":"10.1007/s00601-024-01971-9","url":null,"abstract":"<div><p>We present the experimental apparatus enabling the observation of the heteronuclear Efimov effect in an optically trapped ultracold mixture of <span>(^6)</span>Li-<span>(^{133})</span>Cs with high-resolution control of the interactions. A compact double-species Zeeman slower consisting of four interleaving helical coils allows for a fast-switching between two optimized configurations for either Li or Cs and provides an efficient sequential loading into their respective MOTs. By means of a bichromatic optical trapping scheme based on species-selective trapping we prepare mixtures down to 100 nK of <span>({1times 10^{4}})</span> Cs atoms and <span>({7times 10^{3}})</span> Li atoms. Highly stable magnetic fields allow high-resolution atom-loss spectroscopy and enable to resolve splitting in the loss feature of a few tens of milligauss. These features allowed for a detailed study of the Efimov effect.</p></div>","PeriodicalId":556,"journal":{"name":"Few-Body Systems","volume":"66 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2024-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00601-024-01971-9.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142737153","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}

{"title":"Investigation of the nature of the wind interaction in HD 93205 based on multi-epoch X-ray observations","authors":"Bharti Arora, Michaël De Becker","doi":"10.1051/0004-6361/202451681","DOIUrl":"https://doi.org/10.1051/0004-6361/202451681","url":null,"abstract":"<i>Context<i/>. The study of the X-ray emission from massive binaries constitutes a relevant approach to investigate shock physics. The case of short period binaries may turn out to be quite challenging, especially in very asymmetric systems where the primary wind may overwhelm that of the secondary in the wind interaction.<i>Aims<i/>. Our objective consists in providing an observational diagnostic of the X-ray behavior of HD 93205, which is a very good candidate with which to investigate these aspects.<i>Methods<i/>. We analyzed 31 epochs of <i>XMM-Newton<i/> X-ray data spanning about two decades to investigate its spectral and timing behavior.<i>Results<i/>. The X-ray spectrum is very soft along the full orbit, with a luminosity exclusively from the wind interaction region in the range of 2.3–5.4×10<sup>32<sup/> erg s<sup>−1<sup/>. The light curve peaks close to periastron, with a rather wide pre-periastron low state coincident with the secondary’s body hiding a part of the X-ray emitting region close to its surface. We determined a variability timescale of 6.0807 ± 0.0013 d, in full agreement with the orbital period. Making use of a one-dimensional approach to deal with mutual radiative effects, our results point to a very likely hybrid wind interaction, with a wind photosphere occurring along most of the orbit, while a brief episode of wind-wind interaction may still develop close to apastron. Besides mutual radiative effects, the radiative nature of the shock that leads to some additional pre-shock obliquity of the primary wind flow certainly explains the very soft emission.<i>Conclusions<i/>. HD 93205 constitutes a relevant target to investigate shock physics in short period, asymmetric massive binary systems, where various mutual radiative effects and radiative shocks concur to display an instructive soft X-ray behavior. HD 93205 should be considered as a valid, though challenging target for future three-dimensional modeling initiatives.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"27 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2024-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142758349","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":"An unusual phase transition in a non-Hermitian Su-Schrieffer-Heeger model.","authors":"A Niveth, S Karthiga, M Senthilvelan","doi":"10.1088/1361-648X/ad9448","DOIUrl":"10.1088/1361-648X/ad9448","url":null,"abstract":"<p><p>This article studies a non-Hermitian Su-Schrieffer-Heeger model which has periodically staggered Hermitian and non-Hermitian dimers. The changes in topological phases of the considered chiral symmetric model with respect to the introduced non-Hermiticity are studied where we find that the system supports only complex eigenspectra for all values of<i>u</i> ≠ 0 and it stabilizes only non-trivial insulating phase for higher loss-gain strength. Even if the system acts as a trivial insulator in the Hermitian limit, the increase in loss-gain strength induces phase transition to non-trivial insulating phase through a (gapless) semi-metallic phase. Interesting phenomenon is observed in the case where Hermitian system acts as a non-trivial insulator. In such a situation, the introduced non-Hermiticity neither leaves the non-trivial phase undisturbed nor induces switching to trivial phase. Rather, it shows transition from non-trivial insulating phase to the same where it is mediated by the stabilization of (non-trivial) semi-metallic phase. This unusual transition between the non-trivial insulating phases through non-trivial semi-metallic phase gives rise to a question regarding the topological states of the system under open boundary conditions. So, we analyze the possibility of stable edge states in these two non-trivial insulating phases and check the characteristic difference between them. In addition, we study the nature of topological states in the case of non-trivial gapless (semi-metallic) region.</p>","PeriodicalId":16776,"journal":{"name":"Journal of Physics: Condensed Matter","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142667507","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":"Translation as a Biosignature.","authors":"Jordan M McKaig, MinGyu Kim, Christopher E Carr","doi":"10.1089/ast.2023.0101","DOIUrl":"https://doi.org/10.1089/ast.2023.0101","url":null,"abstract":"<p><p>Life on Earth relies on mechanisms to store heritable information and translate this information into cellular machinery required for biological activity. In all known life, storage, regulation, and translation are provided by DNA, RNA, and ribosomes. Life beyond Earth, even if ancestrally or chemically distinct from life <i>as we know it,</i> may utilize similar structures: it has been proposed that charged linear polymers analogous to nucleic acids may be responsible for storage and regulation of genetic information in nonterran biochemical systems. We further propose that a ribosome-like structure may also exist in such a system, due to the evolutionary advantages of separating heritability from cellular machinery. In this study, we use a solid-state nanopore to detect DNA, RNA, and ribosomes, and we demonstrate that machine learning can distinguish between biomolecule samples and accurately classify new data. This work is intended to serve as a proof of principal that such biosignatures (<i>i.e.</i>, informational polymers or translation apparatuses) could be detected, for example, as part of future missions targeting extant life on Ocean Worlds. A negative detection does not imply the absence of life; however, the detection of ribosome-like structures could provide a robust and sensitive method to seek extant life in combination with other methods. Key Words<b>:</b> RNA world-Darwinian evolution-Nucleic acids-Agnostic life detection. Astrobiology xx, xxx-xxx.</p>","PeriodicalId":8645,"journal":{"name":"Astrobiology","volume":" ","pages":""},"PeriodicalIF":3.5,"publicationDate":"2024-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142749670","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}

{"title":"Hollow MoS2-Co3S4 heterostructures derived from ZIF-67 as saturable absorber for generating gigahertz repetition frequency mode-locked fiber lasers","authors":"Cheng Lu ,&nbsp;Weiyu Fan ,&nbsp;Xiaoyu Zhao ,&nbsp;Kaixin Li ,&nbsp;Lezheng Wang ,&nbsp;Yutian He ,&nbsp;Huanian Zhang ,&nbsp;Nannan Xu ,&nbsp;Guomei Wang ,&nbsp;Wenfei Zhang ,&nbsp;Caixun Bai ,&nbsp;Shenggui Fu","doi":"10.1016/j.optlastec.2024.112230","DOIUrl":"10.1016/j.optlastec.2024.112230","url":null,"abstract":"<div><div>In practical applications, high repetition frequency (HRF) lasers are widely used in the fields of material processing, laser communication and medical therapy. In this work, the passive harmonic mode-locked (HML) technique is used to realize a HRF fiber laser in GHz level, effectively overcoming the limitations of traditional fiber laser structures. In order to maximize the advantages of nanomaterials, we synthesized high-purity hollow MoS₂-Co₃S₄ heterojunction materials by hydrothermal method. Then, a “sandwich” structure saturable absorber (SA) was prepared by photodeposition, and its nonlinear optical properties were investigated. The results demonstrate that the modulation depth and saturation intensity of MoS₂-Co₃S₄ SA are 24 % and 4.53 MW/cm², respectively. The fiber laser based on MoS₂-Co₃S₄ SA could realize the fundamental frequency mode-locked at 23.11 MHz with a pulse width of 0.99 ps. In addition, various high-order HML are realized with this laser system capable of stable operation for extended periods up to the highest repetition frequency of 1.109 GHz achieved thus far in this field. This research provides strong support to promote the development and commercialization of HRF fiber lasers.</div></div>","PeriodicalId":19511,"journal":{"name":"Optics and Laser Technology","volume":"182 ","pages":"Article 112230"},"PeriodicalIF":4.6,"publicationDate":"2024-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142743255","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":"Research on the characterization of reinforced concrete corrosion based on nonlinear coda wave interferometry","authors":"Hongwei Hu ,&nbsp;Zilong Huang ,&nbsp;Chenglong Yang ,&nbsp;Xianghong Wang ,&nbsp;Wenzheng Liu","doi":"10.1016/j.apacoust.2024.110427","DOIUrl":"10.1016/j.apacoust.2024.110427","url":null,"abstract":"<div><div>Reinforced concrete (RC) structures constructed in harsh environments are prone to corrosion, inducing a shorter lifespan. It is particularly important to monitor the RC corrosion in order to eliminate safety hazards. A novel method based on the nonlinear coda wave interferometry (NCWI) technique is proposed in the paper for the characterization of corrosion in reinforced concrete (RC) structures. By establishing the RC rapid corrosion experimental system, the variations of coda wave eigenvalues (Δ<em>v/v</em> and <em>K_d</em>) with the amplitude of the pump wave in RC samples are studied. The results show that: Δ<em>v/v</em> exhibits a strong linear relationship with the pump wave amplitude, while <em>K_d</em> shows a quadratic correlation with the pump wave amplitude in the corroded sample; NCWI can distinguish the corroded and intact RC samples efficiently. This study is expected to contribute to the advancement of ultrasonic testing techniques and the monitoring of reinforced concrete (RC) corrosion.</div></div>","PeriodicalId":55506,"journal":{"name":"Applied Acoustics","volume":"230 ","pages":"Article 110427"},"PeriodicalIF":3.4,"publicationDate":"2024-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142746120","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":"Hawking radiation in quantum Hall system with an expanding edge: Application of anomaly method","authors":"Riku Yoshimoto,&nbsp;Yasusada Nambu","doi":"10.1016/j.physleta.2024.130100","DOIUrl":"10.1016/j.physleta.2024.130100","url":null,"abstract":"<div><div>The relationship between gravitational anomalies and Hawking radiation of black holes was revealed by Wilczek and Robinson. In this study, we apply their method to an analogue de Sitter spacetime in the quantum Hall system with an expanding edge. The chiral nature of the system eliminates the need for imposing the condition of ingoing modes near the horizon. Moreover, this system is structured so that the de Sitter space is sandwiched between two flat spaces, and although the effects of the anomaly would not appear in an ordinal de Sitter spacetime, they manifest themselves as boundary conditions between the de Sitter and the flat regions. By performing calculations under these boundary conditions, we obtain the flux of Hawking radiation in the outer flat region with the Gibbons-Hawking temperature of the de Sitter horizon.</div></div>","PeriodicalId":20172,"journal":{"name":"Physics Letters A","volume":"529 ","pages":"Article 130100"},"PeriodicalIF":2.3,"publicationDate":"2024-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142747442","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}

{"title":"Anisotropic magnetic interactions in a candidate Kitaev spin liquid close to a metal-insulator transition","authors":"Zeyu Ma,&nbsp;Danrui Ni,&nbsp;David A. S. Kaib,&nbsp;Kylie MacFarquharson,&nbsp;John S. Pearce,&nbsp;Robert J. Cava,&nbsp;Roser Valentí,&nbsp;Radu Coldea,&nbsp;Amalia I. Coldea","doi":"10.1038/s42005-024-01873-6","DOIUrl":"10.1038/s42005-024-01873-6","url":null,"abstract":"In the Kitaev honeycomb model, spins coupled by strongly-frustrated anisotropic interactions do not order at low temperature but instead form a quantum spin liquid with spin fractionalisation into Majorana fermions and static fluxes. The realization of such a model in crystalline materials could lead to major breakthroughs in understanding entangled quantum states, however achieving this in practice is a very challenging task. The recently synthesized honeycomb material RuI3 shows no long-range magnetic order down to the lowest probed temperatures and has been theoretically proposed as a quantum spin liquid candidate material on the verge of an insulator to metal transition. Here we report a comprehensive study of the magnetic anisotropy in un-twinned single crystals via torque magnetometry and detect clear signatures of strongly anisotropic and frustrated magnetic interactions. We attribute the development of sawtooth and six-fold torque signal to strongly anisotropic, bond-dependent magnetic interactions by comparing to theoretical calculations. As a function of magnetic field strength at low temperatures, torque shows an unusual non-parabolic dependence suggestive of a proximity to a field-induced transition. Thus, RuI3, without signatures of long-range magnetic order, displays key hallmarks of an exciting candidate for extended Kitaev magnetism with enhanced quantum fluctuations. Quantum spin liquids are materials predicted to be absent of magnetic ordering at low temperature, giving rise to fractionalised electronic states, but conclusive experimental evidence is still absent. Here, the authors conduct angular dependent torque measurements on the candidate spin liquid material RuI3 and, through a comparison of experimental and theoretical results, provide evidence indicating the presence of frustrated magnetic interactions in the system.","PeriodicalId":10540,"journal":{"name":"Communications Physics","volume":" ","pages":"1-8"},"PeriodicalIF":5.4,"publicationDate":"2024-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s42005-024-01873-6.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142758097","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}

{"title":"Spectrum and energy levels of the high-lying singly excited configurations of Nd III","authors":"M. Ding, A. N. Ryabtsev, E. Y. Kononov, T. Ryabchikova, J. C. Pickering","doi":"10.1051/0004-6361/202451652","DOIUrl":"https://doi.org/10.1051/0004-6361/202451652","url":null,"abstract":"<i>Aims<i/>. We aim to accurately determine bound-to-bound transition wavelengths and energy levels of the high-lying open-shell configurations 4f<sup>3<sup/>7s, 4f<sup>3<sup/>6d, and 4f<sup>3<sup/>5f of doubly ionised neodymium (Nd III, <i>Z<i/> = 60) through high-resolution spectroscopy and semi-empirical calculations. This study is motivated by lanthanide atomic data requirements in astronomy, such those involved in investigations of kilonova spectra.<i>Methods<i/>. Fourier transform spectra of Nd Penning and hollow cathode discharge lamps were recorded within the region 32500–54000 cm<sup>−1<sup/> (3077–1852 Å) and grating spectra of Nd vacuum sliding sparks were recorded within the regions 820–1159 Å and 1600–3250 Å. New energy levels were found using the observed wavelengths measured accurate to a few parts in 10<sup>8<sup/> in Fourier transform spectra and to a few parts in 10<sup>7<sup/> in grating spectra. Atomic structure and transition probability calculations of Nd III were carried out using the Cowan codes, where energy parameters were adjusted to fit all known Nd III levels. Finally, Nd-rich stellar spectra were also used to aid in the analysis.<i>Results<i/>. In total, 355 transitions were classified from observed spectra involving 116 previously experimentally unknown energy levels of the 4f<sup>3<sup/>7s, 4f<sup>3<sup/>6d, and 4f<sup>3<sup/>5f configurations of Nd III, all reported here for the first time. Three newly identified levels of the 4f<sup>3<sup/>5d configuration and one newly identified 4f<sup>4<sup/> level are also reported. Typical level energy uncertainties are 0.01 cm<sup>−1<sup/> for the 4f<sup>3<sup/>7s and 4f<sup>3<sup/>6d levels and 0.3 cm<sup>−1<sup/> for the 4f<sup>3<sup/>5f levels. In addition, calculated energy levels up to 130 936 cm<sup>−1<sup/> are presented, including eigenvector composition and calculated level lifetimes. Calculated transition probabilities and wavelengths between 1900–50 000 Å are also given. Using newly established levels of the 4f<sup>3<sup/>7s configuration and the recently established levels of the 4f<sup>3<sup/>6s configuration, the ionisation energy of Nd III has been estimated at 178 090 ± 330 cm<sup>−1<sup/>. This result offers up to twice the accuracy of the most recently published value.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"15 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2024-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142758353","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":"Manipulating Floquet-driven topological insulator with off-resonant elliptically polarized light in presence of hexagonal fermi surface warping.","authors":"Neetu Agrawal","doi":"10.1088/1361-648X/ad98db","DOIUrl":"https://doi.org/10.1088/1361-648X/ad98db","url":null,"abstract":"<p><p>The irradiation of topological insulator surface with elliptically polarized light modifies the topological properties in a phase-dependent manner impacting the Floquet Chern number which is a crucial topological invariant associated with such driven systems. Employing Floquet theory in presence of hexagonal warping term in the Dirac fermion Hamiltonian under off-resonant conditions, we derive an effective Hamiltonian that highlights distinct features in the Floquet-Dirac surface states. Specifically, we identify a helicity and ellipticity-dependent mass term in the quasi-static Hamiltonian, breaking time reversal symmetry. This mass term changes sign with variations in the helicity and ellipticity of incident radiation, potentially driving the system into trivial or Floquet-Chern topological insulating phases. We calculate the Berry curvature associated with the bandstructure and the resulting anomalous Hall conductivity, finding a strong dependence on the ellipticity and amplitude of the radiation.</p>","PeriodicalId":16776,"journal":{"name":"Journal of Physics: Condensed Matter","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142755218","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}