Journal of Physics: Condensed Matter最新文献_第3页

Message-passing neural network for magnetic phase transition simulation. 磁相变仿真的消息传递神经网络。

IF 2.3 4区物理与天体物理

Journal of Physics: Condensed Matter Pub Date : 2025-05-19 DOI: 10.1088/1361-648X/add4dc

Shuhao Hu, Xinjian Ouyang, Zhilong Wang, Feng Zhang, Dawei Wang

{"title":"Message-passing neural network for magnetic phase transition simulation.","authors":"Shuhao Hu, Xinjian Ouyang, Zhilong Wang, Feng Zhang, Dawei Wang","doi":"10.1088/1361-648X/add4dc","DOIUrl":"10.1088/1361-648X/add4dc","url":null,"abstract":"Predicting magnetic phase transitions traditionally relies on a Hamiltonian model to capture key magnetic interactions. Recent advances in machine learning enables the development of a unified approach that can handle diverse magnetic systems without designing new Hamiltonians for each case. To this end, we employ message-passing neural network (MPNN) potentials to investigate magnetic phase transitions of two-dimensional chromium trihalidesCrX3(X = I, Br, Cl) . We achieve this by introducing a specialized MPNN with the ability to incorporate the magnetic degrees of freedom. This magnetic MPNN incorporates atomic magnetic moments directly into the message-passing process, enabling accurate modeling of potential energy surfaces in magnetic materials. This approach improves on our previous work, which had the same aim but used Behler-Parrinello neural network that relies on hand-crafted descriptors as the underlying universal magnetic Hamiltonian. It also adds the capability to treat magnetic degrees of freedom and atom displacement in a unified way. Using two-dimensionalCrX3as examples and combining the MPNN with the Landau-Lifshitz-Gilbert equation, we simulate ferromagnetic and antiferromagnetic phase transitions as a function of temperature. These results highlight the potential of MPNNs for advancing research in magnetic materials.","PeriodicalId":16776,"journal":{"name":"Journal of Physics: Condensed Matter","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2025-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143970869","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}

引用次数: 0

Anisotropy driven spin-reorientation, and two-step magnetic ordering in cubic semiconducting spinelCr0.1Mn0.9Fe0.2Co1.8O4. 立方半导体尖晶石Cr0.1Mn0.9Fe0.2Co1.8O4中各向异性驱动的自旋重定向和两步磁有序。

IF 2.3 4区物理与天体物理

Journal of Physics: Condensed Matter Pub Date : 2025-05-19 DOI: 10.1088/1361-648X/add63d

A D Singha, M S Seehra, M Skoulatos, T Sarkar, P Pramanik, S Chowdhury, M Hoesch, M Reehuis, D M Többens, A Raghu, S D Kaushik, S Thota

{"title":"Anisotropy driven spin-reorientation, and two-step magnetic ordering in cubic semiconducting spinelCr0.1Mn0.9Fe0.2Co1.8O4.","authors":"A D Singha, M S Seehra, M Skoulatos, T Sarkar, P Pramanik, S Chowdhury, M Hoesch, M Reehuis, D M Többens, A Raghu, S D Kaushik, S Thota","doi":"10.1088/1361-648X/add63d","DOIUrl":"10.1088/1361-648X/add63d","url":null,"abstract":"The nature of magnetism in the cubic spinelCr0.1Mn0.9Fe0.2Co1.8O4is reported based on systematic investigations by means of magnetization (M), ac susceptibility (χ) and heat capacity (CP) measurements, as well as by neutron diffraction. Structural characterization of the sample was done usingx-ray absorption spectroscopy, neutron and synchrotron diffraction. TheMvs.Tvariation in different magnetic fields indicate ferrimagnetic ordering belowTC= 230 K, followed by a magnetic field and anisotropy induced spin reorientation atTSR∼150 K. With increasingTstarting from 2 K, the coercivityHCand anisotropy fieldHKdecrease and become negligible forT>TSR. A model to explain theHCvs.Tdata shows thatTSRis due to reorientation ofMalongHwhenH>HK. TheCPvs.Tdata shows a weakλ-type anomaly atTCwith changes in magnetic entropy smaller than those observed belowTSRsuggesting that long-range magnetic ordering is completed belowTSR. ForTSR<T<TC, the presence of weakly interacting magnetic clusters having weak short-range interactions is evident based on analysis of magnetization and ac susceptibilities. Exchange constants (JAA/kB= 7.9 K,JAB/kB= 22.6 K andJBB/kB= -5.3 K) are determined from the temperature dependence of paramagnetic susceptibility forT>TC. This analysis also shows the low-spinS= 0 state of Co3+ions on theBsites which along with negligibleHKforTSR<T<TCproduces weakly interacting magnetic clusters in this magnetic semiconductor with bandgap ∼0.57 eV.","PeriodicalId":16776,"journal":{"name":"Journal of Physics: Condensed Matter","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2025-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143977621","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}

引用次数: 0

Prediction of the mechanical properties of graphene/copper nanocomposites using machine learning and molecular dynamics simulations. 利用机器学习和分子动力学模拟预测石墨烯/铜纳米复合材料的力学性能。

IF 2.3 4区物理与天体物理

Journal of Physics: Condensed Matter Pub Date : 2025-05-19 DOI: 10.1088/1361-648X/add2c2

Tinghong Gao, Lei Chen, Bei Wang, Yutao Liu, Yong Ma, Yongchao Liang

{"title":"Prediction of the mechanical properties of graphene/copper nanocomposites using machine learning and molecular dynamics simulations.","authors":"Tinghong Gao, Lei Chen, Bei Wang, Yutao Liu, Yong Ma, Yongchao Liang","doi":"10.1088/1361-648X/add2c2","DOIUrl":"10.1088/1361-648X/add2c2","url":null,"abstract":"Doping graphene into copper monomers significantly enhances their mechanical properties, thereby broadening the application scope of graphene/copper nanocomposites. Molecular dynamics (MD) simulation serve as a powerful tool for investigating the mechanical behavior of these nanocomposites. This study systematically explores the influence of four critical factors-external temperature, graphene vacancy defects, graphene chirality, and insertion angle-on the performance of graphene/copper nanocomposites. However, the simultaneous analysis of these factors through MD simulations substantially escalates computational demands. To address the computational bottleneck of MD simulations in analyzing multifactorial interactions, we integrate LSTM networks and back propagation (BP) neural networks for dual-task prediction: (1) LSTM captures the complete tensile stress-strain behavior (300 time steps per case) by learning sequential MD data, and (2) BP networks predict Young's modulus and yield strength from critical parameters (temperature, chirality, vacancy defects). Results demonstrate that the LSTM model achievesR2= 0.96 for Young's modulus andR2= 0.94 for yield strength prediction, while the BP neural network further improves accuracy toR2= 0.97 for both properties. Notably, the LSTM model predicts the entire tensile process in 2.4 s per curve, reducing computational time by three orders of magnitude compared to MD simulations (typically requiring hours). Furthermore, LSTM effectively helps elucidate the whole tensile process of the composites, which enhances the ability to predict material properties.","PeriodicalId":16776,"journal":{"name":"Journal of Physics: Condensed Matter","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2025-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144024346","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}

引用次数: 0

Theoretical investigation of the superconducting pairing symmetry in a bilayer two-orbital model of pressurized La₃Ni₂O₇. 加压La3Ni2O7双层双轨模型超导对对称性的理论研究。

IF 2.3 4区物理与天体物理

Journal of Physics: Condensed Matter Pub Date : 2025-05-19 DOI: 10.1088/1361-648X/add6fc

Yi Gao

引用次数: 0

Variational quantum-algorithm based self-consistent calculations for the two-site DMFT model on noisy quantum computing hardware. 基于变分量子算法的二元DMFT模型在噪声量子计算硬件上的自洽计算。

IF 2.3 4区物理与天体物理

Journal of Physics: Condensed Matter Pub Date : 2025-05-16 DOI: 10.1088/1361-648X/add4db

Jannis Ehrlich, Daniel F Urban, Christian Elsässer

{"title":"Variational quantum-algorithm based self-consistent calculations for the two-site DMFT model on noisy quantum computing hardware.","authors":"Jannis Ehrlich, Daniel F Urban, Christian Elsässer","doi":"10.1088/1361-648X/add4db","DOIUrl":"10.1088/1361-648X/add4db","url":null,"abstract":"Dynamical ean field theory (DMFT) is one of the powerful computational approaches to study electron correlation effects in solid-state materials and molecules. Its practical applicability is, however, limited by the quantity of numerical resources required for the solution of the underlying auxiliary Anderson impurity model. Here, the one-to-one mapping between electronic orbitals and the state of a qubit register suggests a significant computational advantage for the use of a quantum computer (QC) for solving this task. In this work we present a QC approach to solve a two-site DMFT model based on the variational quantum eigensolver (VQE) algorithm. We analyze the propagation of stachastic and device errors through the algorithm and their effects on the calculated self-energy. Therefore, we systematically compare results obtained on simulators with calculations on the IBMQ Ehningen QC hardware. We suggest a means to overcome unphysical features in the self-energy which already result from purely stochastic noise. Based heron, we demonstrate the feasibility to obtain self-consistent results of the two-site DMFT model based on VQE simulations with a finite number of shots.","PeriodicalId":16776,"journal":{"name":"Journal of Physics: Condensed Matter","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2025-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143970834","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}

引用次数: 0

Pressure-tuned magnetism and conductivity in pyrochlore iridates Lu2Ir2O7 and Er2Ir2O7. 焦绿石铱酸盐Lu2Ir2O7和Er2Ir2O7的压力调谐磁性和电导率。

IF 2.3 4区物理与天体物理

Journal of Physics: Condensed Matter Pub Date : 2025-05-15 DOI: 10.1088/1361-648X/add97e

Daniel Staško, Petr Proschek, Jiří Prchal, Milan Klicpera

{"title":"Pressure-tuned magnetism and conductivity in pyrochlore iridates Lu2Ir2O7 and Er2Ir2O7.","authors":"Daniel Staško, Petr Proschek, Jiří Prchal, Milan Klicpera","doi":"10.1088/1361-648X/add97e","DOIUrl":"https://doi.org/10.1088/1361-648X/add97e","url":null,"abstract":"A2Ir2O7 iridates were proven to crystallise in the geometrically frustrated pyrochlore structure, which remains stable upon rare-earth cation substitution, temperature variation, and external pressure application. However, the change of interatomic distances and local distortions in the lattice frequently leads to complex electronic properties. The low-temperature behaviour in light-A iridates has been thoroughly investigated, including its evolution with pressure. The present pressure study reports the electrical transport and magnetotransport properties in heavy rare-earth Lu2Ir2O7 and Er2Ir2O7. Both compounds reveal a semiconductor-insulator transition induced by the antiferromagnetic ordering of the all-in-all-out (AIAO) type in the Ir sublattice. The transition monotonously shifts to a higher temperature under applied pressure by approximately 20 K at 3 GPa. As the transition in resistivity originates in the antiferromagnetic order, the latter is expected to be enhanced with the applied pressure as well. Upon cooling the compound in a magnetic field, the AIAO/AOAI domain structure with non-zero net magnetic moment is formed, mirroring itself in an asymmetric term in the magnetoresistivity of Lu2Ir2O7. The application of pressure then enhances the asymmetric term. The same behaviour is proposed for the whole heavy rare-earth A2Ir2O7 series (A = Gd - Lu), although with magnetoresistivity features masked significantly by a stronger response of magnetic A cations.&#xD.","PeriodicalId":16776,"journal":{"name":"Journal of Physics: Condensed Matter","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2025-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144078610","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}

引用次数: 0

Water dissociation in CNT-supported IrO₂nanoparticles. 碳纳米管负载iro2纳米颗粒中的水解离。

IF 2.3 4区物理与天体物理

Journal of Physics: Condensed Matter Pub Date : 2025-05-13 DOI: 10.1088/1361-648X/add2c0

José Luis Nuñez, Gustavo Daniel Belletti, Frederik Tielens, Paola Quaino

引用次数: 0

Non-linear charge currents and the planar Hall effect in quantum wells with Rashba and Dresselhaus spin-orbit interactions. 具有Rashba和Dresselhaus自旋轨道相互作用的量子阱中的非线性电荷流和平面霍尔效应。

IF 2.3 4区物理与天体物理

Journal of Physics: Condensed Matter Pub Date : 2025-05-12 DOI: 10.1088/1361-648X/add3e9

Abhishek Khanal, D C Marinescu

{"title":"Non-linear charge currents and the planar Hall effect in quantum wells with Rashba and Dresselhaus spin-orbit interactions.","authors":"Abhishek Khanal, D C Marinescu","doi":"10.1088/1361-648X/add3e9","DOIUrl":"https://doi.org/10.1088/1361-648X/add3e9","url":null,"abstract":"We calculate the non-linear charge currents in a two-dimensional electron system with Rashba (α) and Dresselhaus (β) linear spin-orbit interactions (SOIs) in the presence of in-plane electricEand magneticBfields. Working in a rotated system of coordinates that introducesα±βas effective couplings on perpendicular directions, we show that the currents, quadratic in the electric field, exist for all values of the chemical potentialµ, above or below the band crossing energyE0. Our formalism uses a second order correction to the particle distribution functionδf(2)derived in a semi-classical approximation that takes into account the local change in the single-particle energy under the action of the electric field. In a quantum well, whereμ>E0, for a spin-orbit energy larger than the Zeeman splitting, the non-linear currents that flow perpendicular on the direction of the magnetic field are found to be proportional withα±βwhenE⊥Band with(α±β)2/(α∓β)whenE∥B, a result independent of the presence of any additional SOIs, such as the cubic Dresselhaus or warping.","PeriodicalId":16776,"journal":{"name":"Journal of Physics: Condensed Matter","volume":"37 22","pages":""},"PeriodicalIF":2.3,"publicationDate":"2025-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144030441","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}

引用次数: 0

Anomalous behaviors in dynamical quantum phase transitions of long-range topological chains. 远距离拓扑链动态量子相变中的异常行为。

IF 2.3 4区物理与天体物理

Journal of Physics: Condensed Matter Pub Date : 2025-05-12 DOI: 10.1088/1361-648X/add3a5

J E C Carmelo, Wing Chi Yu, P D Sacramento

引用次数: 0

Fast polarized neutron imaging for estimating screening current in superconducting multifilamentary YBCO tape. 用快极化中子成像估计超导多丝YBCO带的筛选电流。

IF 2.3 4区物理与天体物理

Journal of Physics: Condensed Matter Pub Date : 2025-05-12 DOI: 10.1088/1361-648X/add2bd

Cédric Holme Qvistgaard, Luise Theil Kuhn, Morten Sales, Takenao Shinohara, Anders C Wulff, Mette Bybjerg Brock-Hansen, Søren Schmidt

{"title":"Fast polarized neutron imaging for estimating screening current in superconducting multifilamentary YBCO tape.","authors":"Cédric Holme Qvistgaard, Luise Theil Kuhn, Morten Sales, Takenao Shinohara, Anders C Wulff, Mette Bybjerg Brock-Hansen, Søren Schmidt","doi":"10.1088/1361-648X/add2bd","DOIUrl":"https://doi.org/10.1088/1361-648X/add2bd","url":null,"abstract":"In this paper we showcase the strengths of polarized neutron imaging as a magnetic imaging technique through a case study on field-cooled multifilamentary YBCO tape carrying a transport current while containing a trapped magnetic field. The measurements were done at J-PARC's RADEN beamline, and the analysis is based on a radiograph of a single polarization component, to showcase the analysis potential for fast measurements with short acquisition time. Regions of internal damage are easily and accurately identified as the technique probes the internal magnetic field of the sample directly. Quantitative measurements of the integrated field strength in various regions are acquired using time-of-flight information. Finally, the strength of the screening currents in each filament of the superconductor are estimated by simulating an experiment with a model sample and comparing it to data. With this, we show that polarized neutron imaging is not only a useful tool for investigating magnetic structures but also for investigating currents.","PeriodicalId":16776,"journal":{"name":"Journal of Physics: Condensed Matter","volume":"37 22","pages":""},"PeriodicalIF":2.3,"publicationDate":"2025-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143970785","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}

引用次数: 0