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npj Computational Materials 2023年第1期9卷 1482-1491页

作者： Bruno Focassio Michelangelo Domina Urvesh Patil Adalberto Fazzio stefano sanvito Federal University of ABC(UFABC) Santo AndréSão Paulo 09210-580Brazil Ilum School of Science CNPEMCampinasSão Paulo 13083-970Brazil School of Physics and CRANN Institute Trinity College DublinDublin 2Ireland

Kohn–Sham density functional theory(KS-DFT)is a powerful method to obtain key materials’properties,but the iterative solution of the KS equations is a numerically intensive task,which limits its application to complex *** address this issue,machine learning(ML)models can be used as surrogates to find the ground-state charge density and reduce the computational *** develop a grid-centred structural representation,based on Jacobi and Legendre polynomials combined with a linear regression,to accurately learn the converged DFT charge *** integrates into a ML pipeline that can return any density-dependent observable,including energy and forces,at the quality of a converged DFT calculation,but at a fraction of the computational *** scanning of energy landscapes and producing starting densities for the DFT self-consistent cycle are among the applications of our scheme.

关键词： density charge Legendre

A rule-free workflow for the automated generation of databases from scientific literature

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npj Computational Materials 2023年第1期9卷 96-109页

作者： Luke P.J.Gilligan Matteo Cobelli Valentin Taufour stefano sanvito School of Physics AMBER and CRANN InstituteTrinity CollegeDublin 2DublinIreland Department of Physics and Astronomy University of CaliforniaDavisCA 95616USA

In recent times,transformer networks have achieved state-of-the-art performance in a wide range of natural language processing *** we present a workflow based on the fine-tuning of BERT models for different downstream tasks,which results in the automated extraction of structured information from unstructured natural language in scientific *** to existing methods for the automated extraction of structured compound-property relations from similar sources,our workflow does not rely on the definition of intricate grammar ***,it can be adapted to a new task without requiring extensive implementation efforts and *** test our data-extraction workflow by automatically generating a database for Curie temperatures and one for band *** are then compared with manually curated datasets and with those obtained with a state-of-the-art rule-based ***,in order to showcase the practical utility of the automatically extracted data in a material-design workflow,we employ them to construct machine-learning models to predict Curie temperatures and band *** general,we find that,although more noisy,automatically extracted datasets can grow fast in volume and that such volume partially compensates for the inaccuracy in downstream tasks.

关键词： automated rule adapted

Edge superconductivity in multilayer WTe2 Josephson junction

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National Science Review 2020年第9期7卷 1468-1475页

作者： Ce Huang Awadhesh Narayan Enze Zhang Xiaoyi Xie Linfeng Ai Shanshan Liu Changjiang Yi Youguo Shi stefano sanvito Faxian Xiu State Key Laboratory of Surface Physics and Department of Physics Fudan University Collaborative Innovation Center of Advanced Microstructures SSCU Indian Institute of Science Institute of Physics and Beijing National Laboratory for Condensed Matter Physics Chinese Academy of Sciences School of Physical Sciences University of Chinese Academy of Sciences School of Physics AMBER and CRANN Institute Trinity College Institute for Nanoelectronic Devices and Quantum Computing Fudan University

WTe2, as a type-II Weyl semimetal, has 2D Fermi arcs on the (001) surface in the bulk and 1D helical edge states in its monolayer. These features have recently attracted wide attention in condensed matter ***, in the intermediate regime between the bulk and monolayer, the edge states have not been resolved owing to its closed band gap which makes the bulk states dominant. Here, we report the signatures of the edge superconductivity by superconducting quantum interference measurements in multilayer WTe2Josephson junctions and we directly map the localized supercurrent. In thick WTe2(～ 60 nm), the supercurrent is uniformly distributed by bulk states with symmetric Josephson effect(|Ic~+(B)|=|Ic~-(B)|).In thin WTe2(10 nm), however, the supercurrent becomes confined to the edge and its width reaches up to 1.4 μm and exhibits non-symmetric behavior |Ic~+(B)|≠|Ic~-(B)|. The ability to tune the edge domination by changing thickness and the edge superconductivity establishes WTe2as a promising topological system with exotic quantum phases and a rich physics.

关键词： WTe2 Josephson junction Weyl semimetal edge superconductivity non-symmetric effect

Purely one-dimensional ferroelectricity and antiferroelectricity from van der Waals niobium oxide trihalides

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npj Computational Materials 2021年第1期7卷 1225-1231页

作者： Lei Zhang Cheng Tang stefano sanvito Aijun Du School of Chemistry and Physics Queensland University of TechnologyBrisbaneAustralia Centre for Materials Science Queensland University of TechnologyBrisbaneAustralia School of Physics and CRANN Institute Trinity CollegeDublin 2Ireland

Intrinsic one-dimensional(1D)ferroelectric materials are rarely reported but are highly sought to break the size limit of nanostructured conventional ***,we report a class of inborn 1D ferroelectric nanowires,namely 1D NbOX_(3)(X=Cl,Br,and I),that can be directly obtained from experimentally realized van der Waals *** addition to the sizable spontaneous polarization,1D NbOX_(3) exhibits low ferroelectric switching barriers,small coercive electric fields,and high critical temperature,governed by the hybridization of the Nb empty d orbitals and the O p orbitals(d^(0) rule).Moreover,the double-channel structure of 1D NbOX_(3) also enables the emergence of 1D antiferroelectric metastable *** findings not only propose a class of 1D ferroelectric materials toward the development of miniaturized and high-density electronic devices,but also pave an avenue of obtaining intrinsic 1D ferroelectrics from van der Waals crystals.

关键词： ferroelectric metastable governed

Selection of Single-Walled Carbon Nanotubes According to Both Their Diameter and Chirality via Nanotweezers

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Nano Research 2010年第4期3卷 296-306页

作者： Jing Zhou Hong Li Jing Lu Guangfu Luo Lin Lai Rui Qin Lu Wang Shigeru Nagase Zhengxiang Gao Waining Mei Guangping Li Dapeng Yu stefano sanvito State Key Laboratory of Mesoscopic Physics and Department of Physics Peking UniversityBeijing 100871China Department of Theoretical Molecular Science Institute for Molecular ScienceOkazaki 444-8585Japan Department of Physics University of Nebraska at OmahaOmahaNebraska 68182-0266USA SICAS Center Lee HallSUNY OneontaOneontaNY 13820USA School of Physics and CRANN Trinity CollegeDublin 2Ireland

Diameter- and chirality-dependent interactions between aromatic molecule-based nanotweezers and single-walled carbon nanotubes (SWNTs) are revealed by density functional theory calculations. We found that the threshold diameter of selected SWNTs is determined by the end-to-end distance of the nanotweezer. Large-diameter SWNTs are preferred by a nanotweezer with an obtuse folding angle, whereas small-diameter SWNTs are favored by a nanotweezer with an acute folding angle. The adsorption can be further stabilized by the orientational alignment of the hexagonal rings of the nanotweezer and the SWNT sidewall. Therefore, by taking advantage of the supramolecular recognition ability of the aromatic molecule-based nanotweezer, SWNTs can be enriched with both controllable diameter and chirality.

关键词： Carbon nanotubes nanotweezer selective adsorption density functional theory

Magnetism in Carbon Nanoscrolls: Quasi-Half-Metals and Half-Metals in Pristine Hydrocarbons

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Nano Research 2009年第11期2卷 844-850页

作者： Lin Lai Jing Lu Lu Wang Guangfu Luo Jing Zhou Rui Qin Yu Chen Hong Li Zhengxiang Gao Guangping Li Wai Ning Mei Yutaka Maeda Takeshi Akasaka and stefano sanvito State Key Laboratory for Mesoscopic Physics and Department of Physics Peking UniversityBeijing 100871China Department of Physics University of Nebraska at OmahaOmahaNebraska 68182-0266USA SICAS Center Lee HallSUNY OneontaOneontaNY 13820USA Department of Chemistry Tokyo Gakugei UniversityTokyo 184-8501Japan PRESTO Japan Science and Technology Agency4-1-8 Honcho KawagushiSaitamaJapan Center for Tsukuba Advanced Research Alliance University of TsukubaIbaraki 305-8577Japan School of Physics and CRANN Trinity CollegeDublin 2Ireland

A magnetic ground state is revealed for the first time in zigzag-edged carbon nanoscrolls(ZCNSs)from spin-unrestricted density functional theory *** their flat counterpart-zigzag-edged carbon nanoribbons,which are semiconductors with spin-degenerate electronic structure-ZCNSs show a variety of magnetic configurations,namely spin-selective semiconductors,metals,semimetals,quasi-half-metals,and *** the best of our knowledge,this is the first discovery of quasi-half-metals and half-metals in a pure hydrocarbon without resort to an external electric *** addition,we calculated the spin-dependent transportation of the semiconducting ZCNSs with 12 and 20 zigzag chains,and found that they are 13% and 17% at the Fermi level,respectively,suggesting that ZCNS can be an effective spin filter.

关键词： Carbon nanoscrolls quasi-half-metals half-metals graphene spin-selective spin filter