物理与天体物理最新文献

{"title":"Magnetic properties and electronic structure ofJeff=12square lattice quantum magnet Bi₂ErO₄Cl.","authors":"V K Singh, Seong-Hoon Kim, K Nam, U Jena, K Boya, P Khuntia, E Kermarrec, Kee Hoon Kim, S Bhowal, B Koteswararao","doi":"10.1088/1361-648X/adc6e5","DOIUrl":"10.1088/1361-648X/adc6e5","url":null,"abstract":"<p><p>Two-dimensional (2D) rare-earth-based square lattice (SL) quantum magnets provide a pathway to achieve distinctive ground states characterized by unusual excitations. We investigate the magnetic, heat capacity, structural, and electronic properties of a magnetic system Bi₂ErO₄Cl. This compound features a structurally ideal 2D SL composed of Er³⁺rare-earth magnetic ions. The single-phase polycrystalline sample was synthesized using hydrothermal, followed by a vacuum-sealed tube technique. The analysis of heat capacity and magnetic data indicates that the Er³⁺ion adopts aJeff=12state at low temperatures. Fitting the Curie-Weiss (CW) law to the low-temperature magnetic susceptibility data reveals a CW temperature of approximately -2.1 K, suggesting antiferromagnetic (AFM) interactions between the Er³⁺moments. Our first-principles calculations validate a 2D spin model relevant to the titled Er compound. The presence of AFM interaction between the Er³⁺ions is further confirmed using total energy calculations (DFT+<i>U</i>), aligning with the experimental results. The heat capacity measurements reveal the presence of magnetic long-range order below<i>T</i>_N= 0.47 K. The magnetic heat capacity data follows<i>T</i>^1.8power law dependence below<i>T</i>_N.</p>","PeriodicalId":16776,"journal":{"name":"Journal of Physics: Condensed Matter","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2025-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143742966","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":"Machine learning-assisted study on the thermal transport properties of two-dimensional M₃(C₆O₆)₂(M = Fe, Co, Ni) materials.","authors":"Meng-Jiao Teng, Li-Qin Deng, Pin-Zhen Jia, Wu-Xing Zhou","doi":"10.1088/1361-648X/adc77c","DOIUrl":"10.1088/1361-648X/adc77c","url":null,"abstract":"<p><p>Two-dimensional metal-organic frameworks (MOF) are widely used in electronic devices and energy storage due to their large surface area, abundant active sites, and tunable sizes. A deeper understanding of the thermal transport properties of two-dimensional MOF materials is essential for these applications. In this work, we systematically studied the thermal transport properties of M₃(C₆O₆)₂(M = Fe, Co, Ni) by using a machine learning interatomic potential method combined with the phonon Boltzmann transport equation. The results show that the lattice thermal conductivities of Fe₃(C₆O₆)₂, Co₃(C₆O₆)₂, and Ni₃(C₆O₆)₂at room temperature are 4.0 W mK^-1, 5.5 W mK^-1, and 5.8 W mK^-1, respectively. The differences in thermal conductivity primarily arise from variations in phonon relaxation times, which can be elucidated by examining the three-phonon scattering phase space. Further analysis of bond strengths reveals that the strong bonding between Fe and O impedes phonon propagation through the oxygen atoms, resulting in lower lattice thermal conductivity. Our work provides a fundamental reference for understanding thermal transport in two-dimensional MOF.</p>","PeriodicalId":16776,"journal":{"name":"Journal of Physics: Condensed Matter","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2025-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143753226","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":"A new graphitization setup for radiocarbon dating using accelerator mass spectrometer at Physical Research Laboratory Ahmedabad","authors":"Amzad Hussain Laskar ,&nbsp;Pratheeksha Nayak ,&nbsp;Aishwarya Singh ,&nbsp;Rahul Kumar Agrawal ,&nbsp;Ranjan Kumar Mohanty ,&nbsp;Manan S. Shah ,&nbsp;M.G. Yadava","doi":"10.1016/j.nimb.2025.165698","DOIUrl":"10.1016/j.nimb.2025.165698","url":null,"abstract":"<div><div>A new vacuum system for radiocarbon (¹⁴C) dating has been developed at the Physical Research Laboratory (PRL), Ahmedabad. This system uses zinc as a reducing agent and iron powder as a catalyst to convert CO₂ into graphite, which is then analyzed using Accelerator Mass Spectrometry (AMS) for measuring ¹⁴C content. The system efficiently processes CO₂ from wide range of samples including organic material, carbonates and water. In this paper, we discuss the details of the setup, graphite reduction efficiency, background activity, and measurements of oxalic acid standards alongside ¹⁴C determinations from known international standards. Additionally, the paper outlines the data reduction process for AMS and the procedure for reporting radiocarbon content with uncertainties. The system can handle five samples at a time, with CO₂ reduction efficiency ranging from 50 to 100%. Multiple ¹⁴C age measurements from 12 international standards highlight the system’s precision and reliability.</div></div>","PeriodicalId":19380,"journal":{"name":"Nuclear Instruments & Methods in Physics Research Section B-beam Interactions With Materials and Atoms","volume":"563 ","pages":"Article 165698"},"PeriodicalIF":1.4,"publicationDate":"2025-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143808072","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":"Signature of metal–metal bonding in Ir–Ni–Ta–(B) bulk metallic glasses","authors":"Suppanut Sangphet, Xiaoyang Chen, Chihao Li, Nan Guo, Xiang Ding, Mingxing Li, YanHui Liu, Rui Peng, Haichao Xu, Wei-Hua Wang, Donglai Feng","doi":"10.1063/5.0261826","DOIUrl":"https://doi.org/10.1063/5.0261826","url":null,"abstract":"In bulk metallic glasses, minimizing the total electronic energy is a key factor in glass formation. However, it remains unclear how this energy is minimized, particularly in metallic glasses made up of transition metal elements. In this study, we use synchrotron-based photoemission spectroscopy to investigate the electronic structure of Ir–Ni–Ta–(B) bulk metallic glasses, which are primarily composed of transition metals and have recently been discovered to exhibit exceptional glass-forming ability. We observe distinct chemical shifts in the core levels of Ir and Ta in opposite directions, while the Ni is close to an elemental-like state, suggesting significant Ir–Ta charge transfer and metal–metal bonding in the metallic glass phase. Additionally, a pseudogap at EF suggests an additional contribution from the itinerant electrons to the glass-forming ability, but likely playing a secondary role as it is only observed in Ir35Ni20Ta40B5. Our findings highlight the critical role of metal–metal bonding in facilitating the glass formation of metallic glasses composed of transition metals.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"36 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143813476","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":"Characterizing atmospheric gravity gradient noise for vertical atom interferometers","authors":"John Carlton, Valerie Gibson, Tim Kovachy, Christopher McCabe, Jeremiah Mitchell","doi":"10.1103/physrevd.111.082003","DOIUrl":"https://doi.org/10.1103/physrevd.111.082003","url":null,"abstract":"Terrestrial long-baseline atom interferometer experiments are emerging as powerful tools for probing new fundamental physics, including searches for dark matter and gravitational waves. In the frequency range relevant to these signals, gravity gradient noise (GGN) poses a significant challenge. While previous studies for vertical instruments have focused on GGN induced by seismic waves, atmospheric fluctuations in pressure and temperature also lead to variations in local gravity. In this work, we advance the understanding of atmospheric GGN in vertical atom interferometers, formulating a robust characterization of its impact. We evaluate the effectiveness of underground placement of atom interferometers as a passive noise mitigation strategy. Additionally, we empirically derive global high- and low-noise models for atmospheric pressure GGN and estimate an analogous range for atmospheric temperature GGN. To highlight the variability of temperature-induced noise, we compare data from three prospective experimental sites. Our findings establish atmospheric GGN as comparable to seismic noise in its impact and underscore the importance of including these effects in site selection and active noise monitoring for future experiments. <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":20167,"journal":{"name":"Physical Review D","volume":"89 1","pages":""},"PeriodicalIF":5.0,"publicationDate":"2025-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143813570","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":"Evolution of the transverse-momentum dependent gluon distribution at small x","authors":"Paul Caucal, Edmond Iancu","doi":"10.1103/physrevd.111.074008","DOIUrl":"https://doi.org/10.1103/physrevd.111.074008","url":null,"abstract":"Using the color dipole picture for photon-nucleus interactions at small x</a:mi></a:math> together with the color glass condensate (CGC) effective theory, we demonstrate that the next-to-leading (NLO) order corrections to the cross section for the inclusive production of a pair of hard jets encode not only the Jalilian-Marian, Iancu, McLerran, Weigert, Leonidov and Kovner (JIMWLK) evolution with decreasing <c:math xmlns:c=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><c:mi>x</c:mi></c:math>, but also the Dokshitzer-Gribov-Lipatov-Altarelli-Parisi (DGLAP) evolution of the gluon distribution function and the Collins-Soper-Sterman (CSS) evolution of the gluon transverse momentum dependent (TMD) distribution. The emergent CSS equation takes the form of a rate equation describing the evolution of the dijet distribution in the transverse momentum imbalance <e:math xmlns:e=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><e:msub><e:mi>K</e:mi><e:mo>⊥</e:mo></e:msub></e:math> when increasing the dijet relative momentum <g:math xmlns:g=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><g:msub><g:mi>P</g:mi><g:mo>⊥</g:mo></g:msub></g:math>. All three types of evolution become important when both <i:math xmlns:i=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><i:msub><i:mi>P</i:mi><i:mo>⊥</i:mo></i:msub></i:math> and <k:math xmlns:k=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><k:msub><k:mi>K</k:mi><k:mo>⊥</k:mo></k:msub></k:math> are much larger than the nuclear saturation momentum <m:math xmlns:m=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><m:msub><m:mi>Q</m:mi><m:mi>s</m:mi></m:msub><m:mo stretchy=\"false\">(</m:mo><m:mi>x</m:mi><m:mo stretchy=\"false\">)</m:mo></m:math> and we propose a framework which encompasses all of them. The solution to the JIMWLK equation provides the source term for the DGLAP evolution with increasing <q:math xmlns:q=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><q:msub><q:mi>K</q:mi><q:mo>⊥</q:mo></q:msub></q:math>, which in turn generates the initial condition for the CSS evolution with increasing <s:math xmlns:s=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><s:msub><s:mi>P</s:mi><s:mo>⊥</s:mo></s:msub></s:math>. <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":20167,"journal":{"name":"Physical Review D","volume":"39 1","pages":""},"PeriodicalIF":5.0,"publicationDate":"2025-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143813602","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":"Holographic fermions in the dyonic Gubser-Rocha black hole","authors":"Cheng-Yuan Lu, Xian-Hui Ge, Sang-Jin Sin","doi":"10.1103/physrevd.111.086011","DOIUrl":"https://doi.org/10.1103/physrevd.111.086011","url":null,"abstract":"We investigate the fermionic properties of a dyonic Gubser-Rocha model in the context of gauge/gravity duality. This model incorporates both a magnetic field and momentum relaxation. We have derived this model’s scaling exponent, revealing the influence of the magnetic field and momentum relaxation on low-energy physics. As the magnetic field strength and momentum relaxation increase, the spectral function of the dual field changes significantly. Specifically, we observe variations in the scaling exponent, Fermi momentum, and dispersion relations as the magnetic field increases, highlighting the system’s transition from a Fermi liquid to a non-Fermi liquid, and eventually to an insulating state. Our analysis of the magneto-scattering rate reveals that it is nearly zero in the Fermi liquid region, increases significantly in the non-Fermi liquid region, and ultimately arrives at a maximum value in the insulating state. <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":20167,"journal":{"name":"Physical Review D","volume":"108 1","pages":""},"PeriodicalIF":5.0,"publicationDate":"2025-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143813611","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":"Investigation on all-inorganic perovskite betavoltaic batteries based on MWCNT electrodes","authors":"Haolin Li, Xinxu Yuan, Jingbin Lu, Xiaoyang Guo, Yu Zhang, Hongyi Tian, Haoran Gu, Ke Zhang, Chunmiao Han, Xinrui Liu, Yu Zhang","doi":"10.1063/5.0264258","DOIUrl":"https://doi.org/10.1063/5.0264258","url":null,"abstract":"Perovskite materials have been extensively studied in the field of solar cells, and inorganic perovskites, with their good environmental and radiation stability, high defect tolerance, and high carrier mobility, also have great potential for betavoltaic batteries. In this study, we analyze the potential of all-inorganic perovskite betavoltaic batteries. The metal electrode commonly used in perovskite cell devices, such as Au, has a large effect on β particle incidence. MWCNTs (multi-walled carbon nanotubes) have excellent electrical conductivity, while their loose and porous structure reduces the effect on β particle incidence, which is an ideal electrode for betavoltaic nuclear batteries. Therefore, we propose the FTO/TiO2/CsPbBr3/NiOx/MWCNT structure and explore the prospects of CsPbBr3 in betavoltaic batteries through simulations and experiments. The simulation results in an open-circuit voltage (Voc) of 0.53 V, a short-circuit current (Jsc) of 21.53 nA cm−2, a maximum output power (Pm) of 9.05 nW cm−2, and a conversion efficiency (η) of 2.9%. The experimentally obtained Voc is 0.42 V, Jsc is 12.22 nA cm−2, Pm is 2.55 nW cm−2, and η is 0.8%. This points to the great potential of all-inorganic perovskite materials for betavoltaic batteries.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"199 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143813628","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":"Emission and absorption lines in the photospheric radius expansion bursts of 4U 1820–30","authors":"Wenhui Yu, Zhaosheng Li, Yuanyue Pan, Xuejuan Yang, Yupeng Chen, Shu Zhang, Maurizio Falanga","doi":"10.1051/0004-6361/202453142","DOIUrl":"https://doi.org/10.1051/0004-6361/202453142","url":null,"abstract":"We analyze the emission and absorption lines during photospheric radius expansion (PRE) X-ray bursts from the ultracompact binary 4U 1820–30, observed with the Neutron Star Interior Composition Explorer (NICER). Using Monte Carlo simulations to estimate the significance, we identified a 1 kiloelectron volt (keV) emission line from 14 bursts, a 3 keV absorption line from 12 bursts, and a 1.6 keV absorption line from one burst. By coadding the burst spectra at the maximum radius phase, we detected a 1.034 keV emission line with significance of 14.2<i>σ<i/>, along with absorption lines at 1.64 and 3 keV, with significances of 10.8<i>σ<i/> and 11.7<i>σ<i/>, respectively. The observed energy shifts are consistent with the prediction from the burst-driven wind model, indicating that all three spectral features are produced by the PRE wind. An analysis of the ratios between the emission and absorption line energies suggests that the 1 keV feature is a superposition of several narrower Fe L-shell lines. To evaluate the scientific capabilities of the Hot Universe Baryon Surveyor (HUBS), we simulated mock observations of multiple narrow lines near 1 keV. These results demonstrate that HUBS is well suited for detailed studies of the 1 keV emission line during bursts, offering significant potential to advance our understanding of these phenomena.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"183 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2025-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143813925","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":"The COSMOS Wall at z ∼ 0.73: Quiescent galaxies and their evolution in different environments⋆","authors":"F. R. Ditrani, M. Longhetti, A. Iovino, M. Fossati, S. Zhou, S. Bardelli, M. Bolzonella, O. Cucciati, A. Finoguenov, L. Pozzetti, M. Salvato, M. Scodeggio, L. Tasca, D. Vergani, E. Zucca","doi":"10.1051/0004-6361/202453620","DOIUrl":"https://doi.org/10.1051/0004-6361/202453620","url":null,"abstract":"The evolution of quiescent galaxies is driven by numerous physical processes, often considered to be related to their stellar mass and environment over cosmic time. Tracing their stellar populations can provide insight into the processes that transformed these galaxies into their observed quiescent state. In particular, higher-redshift galaxies, being younger, exhibit more pronounced relative age differences. At early stages, even small differences in age remain significant, whereas as galaxies evolve, these differences become less detectable, making it harder to trace the impact of environmental effects in the local Universe. The COSMOS Wall is a structure at <i>z<i/> ∼ 0.73 that contains a large variety of environments, from rich and dense clusters down to field-like regions. Thus, this sample offers a great opportunity to study the effect of the environment on the quiescent galaxy population. Leveraging high-quality spectroscopic data from the LEGA-C survey, combined with the extensive photometric coverage of the COSMOS2020 catalogue, we performed a full-index and photometry fitting of 74 massive (log <i>M<i/><sub>⋆<sub/>/<i>M<i/><sub>⊙<sub/> = 10.47) quiescent galaxies, deriving their mass-weighted ages, metallicities, and star formation timescales. We characterised the environment in three subsamples: X-ray- and non-X-ray-detected groups and a lower-density subsample similar to the average field. We find a decreasing trend in mass-weighted age with increasing environmental density, with galaxies groups ≳1 Gyr older than those in the field. Conversely, we do not find any significant difference in stellar metallicity between galaxies in X-ray and non-X-ray groups, while we find galaxies with 0.15 dex higher metallicities in the field. Our results indicate that, at <i>z<i/> ∼ 0.7, the environment plays a crucial role in shaping the evolution of massive quiescent galaxies, noticeably affecting both their mass-weighted age and star formation timescale. These results support faster quenching mechanisms, at fixed stellar mass, in the dense X-ray-detected groups compared to the field.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"30 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2025-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143814224","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}