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Electronic Structure of the Weak Topological Insulator Candidate Zintl Ba_(3)Cd_(2)Sb_(4)
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作者 黄杰瑞 张坦 +9 位作者 徐升 饶志成 李佳俊 刘俊德 高顺业 黄耀波 朱文亮 夏天龙 翁红明 钱天 《Chinese Physics Letters》 SCIE EI CAS CSCD 2023年第4期44-49,共6页
One of the greatest triumph of condensed matter physics in the past ten years is the classification of materials by the principle of topology.The existence of topological protected dissipationless surface state makes ... One of the greatest triumph of condensed matter physics in the past ten years is the classification of materials by the principle of topology.The existence of topological protected dissipationless surface state makes topological insulators great potential for applications and hotly studied.However,compared with the prosperity of strong topological insulators,theoretical predicted candidate materials and experimental confirmation of weak topological insulators(WTIs) are both extremely rare.By combining systematic first-principles calculation and angle-resolved photoemission spectroscopy measurements,we have studied the electronic structure of the dark surface of the WTI candidate Zintl Ba_(3)Cd_(2)Sb_(4)and another related material Ba_(3)Cd_(2)As_(4).The existence of two Dirac surface states on specific side surfaces predicted by theoretical calculations and the observed two band inversions in the Brillouin zone give strong evidence to prove that the Ba_(3)Cd_(2)Sb_(4)is a WTI.The spectroscopic characterization of this Zintl Ba_(3)Cd_(2)N_(4)(N = As and Sb) family materials will facilitate applications of their novel topological properties. 展开更多
关键词 properties TOPOLOGICAL RARE
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手性晶体CoSi中拓扑费米弧的电荷不稳定性
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作者 饶志成 胡全欣 +20 位作者 田尚杰 曲青 陈聪润 高顺业 袁震宇 唐岑瑶 樊文辉 黄杰瑞 黄耀波 王利 张露 李坊森 王克东 杨槐馨 翁红明 钱天 徐金朋 蒋坤 雷和畅 孙煜杰 丁洪 《Science Bulletin》 SCIE EI CAS CSCD 2023年第2期165-172,M0003,共9页
拓扑边界态出现在拓扑非平庸态和平庸态之间的边界上,通常是无间隙的或被称为金属态.例如,拓扑绝缘体的表面态是无间隙的狄拉克态.这些金属拓扑边界态往往可以被近自由费米子很好的描述.如果拓扑边界态具有显著的电子-电子相互作用的行... 拓扑边界态出现在拓扑非平庸态和平庸态之间的边界上,通常是无间隙的或被称为金属态.例如,拓扑绝缘体的表面态是无间隙的狄拉克态.这些金属拓扑边界态往往可以被近自由费米子很好的描述.如果拓扑边界态具有显著的电子-电子相互作用的行为,无间隙的边界态会转变为有间隙的有序态,例如密度波态或超导态,这在理论上是非常有趣的,但目前还缺少相关的实验证据.本文报道了在Co Si(001)表面观察到了电子-电子相互作用驱动的、在拓扑边界态上形成的非公度电荷密度波(CDW). CDW的波矢随温度的变化而变化,这与拓扑表面费米弧随温度的演化相吻合. CDW相的取向由费米弧的手性决定,这暗示了CDW与费米弧之间存在直接的联系.该发现将促进在拓扑材料边界上寻找更多相互作用驱动的有序态,例如超导和磁性. 展开更多
关键词 电荷密度波 有序态 拓扑绝缘体 超导态 狄拉克 金属态 表面态
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Exploration of growth conditions of TaAs Weyl semimetal thin film using pulsed laser deposition
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作者 李世恩 林泽丰 +9 位作者 胡卫 闫大禹 陈赋聪 柏欣博 朱北沂 袁洁 石友国 金魁 翁红明 郭海中 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第4期582-586,共5页
Ta As,the first experimentally discovered Weyl semimetal material,has attracted a lot of attention due to its high carrier mobility,high anisotropy,nonmagnetic properties and strong interaction with light.These make i... Ta As,the first experimentally discovered Weyl semimetal material,has attracted a lot of attention due to its high carrier mobility,high anisotropy,nonmagnetic properties and strong interaction with light.These make it an ideal candidate for the study of Weyl fermions and applications in quantum computation,thermoelectric devices,and photodetection.For further basic physics studies and potential applications,large-size and high-quality Ta As films are urgently needed.However,it is difficult to grow As-stoichiometry Ta As films due to the volatilization of As during the growth.To solve this problem,we attempted to grow Ta As films on different substrates using targets with different As stoichiometric ratios via pulsed laser deposition(PLD).In this work,we found that partial As ions of the Ga As substrate are likely to diffuse into the Ta As films during growth,which was preliminarily confirmed by structural characterization,surface topography and composition analysis.As a result,the As content in the Ta As film was improved and the Ta As phase was achieved.Our work presents an effective method for the fabrication of Ta As films using PLD,enabling possible use of the Weyl semimetal film for functional devices. 展开更多
关键词 Weyl semimetal Ta As film pulsed laser deposition
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VASP2KP:k·p Models and Landég-Factors from ab initio Calculations
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作者 章盛 盛昊昊 +8 位作者 宋志达 梁晨昊 蒋毅 孙松 吴泉生 翁红明 方忠 戴希 王志俊 《Chinese Physics Letters》 SCIE EI CAS CSCD 2023年第12期114-125,共12页
The k·p method is significant in condensed matter physics for the compact and analytical Hamiltonian.In the presence of magnetic field,it is described by the effective Zeeman's coupling Hamiltonian with Land&... The k·p method is significant in condensed matter physics for the compact and analytical Hamiltonian.In the presence of magnetic field,it is described by the effective Zeeman's coupling Hamiltonian with Landég-factors.Here,we develop an open-source package VASP2KP(including two parts:vasp2mat and mat2kp)to compute k·p parameters and Landég-factors directly from the wavefunctions provided by the density functional theory(DFT)as implemented in Vienna ab initio Simulation Package(VASP).First,we develop a VASP patch vasp2mat to compute matrix representations of the generalized momentum operatorπ=p+1/2mc^(2)[s×■V(r)],spin operator s,time reversal operatorT,and crystalline symmetry operatorsR on the DFT wavefunctions.Second,we develop a python code mat2kp to obtain the unitary transformation U that rotates the degenerate DFT basis towards the standard basis,and then automatically compute the k·p parameters and g-factors.The theory and the methodology behind VASP2KP are described in detail.The matrix elements of the operators are derived comprehensively and computed correctly within the projector augmented wave method.We apply this package to some materials,e.g.,Bi2Se3,Na3Bi,Te,InAs and 1H-TMD monolayers.The obtained effective model's dispersions are in good agreement with the DFT data around the specific wave vector,and the g-factors are consistent with experimental data.The VASP2KP package is available at https://github.com/zjwang11/VASP2KP. 展开更多
关键词 method OPERATORS OPERATOR
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凝聚态物质科学科研数据管理与应用 被引量:2
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作者 王丹 周明波 +9 位作者 黄东宸 李云龙 林泽丰 刘俊德 朱天念 竺云 李明星 肖睿娟 袁洁 翁红明 《科学通报》 EI CAS CSCD 北大核心 2024年第9期1164-1174,共11页
大数据已经以不可阻挡的脚步踏入了社会生活,大到国家范围流行病趋势的准确预测[1]、纳斯达克上市公司市值估算(http://busmiamiedu/umbfc/common/files/papers/Karabulutpdf);小到机票最佳购买时机的选择[2]、出行自动导航等[3].作为... 大数据已经以不可阻挡的脚步踏入了社会生活,大到国家范围流行病趋势的准确预测[1]、纳斯达克上市公司市值估算(http://busmiamiedu/umbfc/common/files/papers/Karabulutpdf);小到机票最佳购买时机的选择[2]、出行自动导航等[3].作为一种新的技术,大数据已对人们的生活、生产带来了深远的变革性影响[4,5]. 展开更多
关键词 上市公司市值 纳斯达克 数据管理与应用 凝聚态物质 自动导航 大数据 变革性
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Literature classification and its applications in condensed matter physics and materials science by natural language processing
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作者 吴思远 朱天念 +5 位作者 涂思佳 肖睿娟 袁洁 吴泉生 李泓 翁红明 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第5期117-123,共7页
The exponential growth of literature is constraining researchers’access to comprehensive information in related fields.While natural language processing(NLP)may offer an effective solution to literature classificatio... The exponential growth of literature is constraining researchers’access to comprehensive information in related fields.While natural language processing(NLP)may offer an effective solution to literature classification,it remains hindered by the lack of labelled dataset.In this article,we introduce a novel method for generating literature classification models through semi-supervised learning,which can generate labelled dataset iteratively with limited human input.We apply this method to train NLP models for classifying literatures related to several research directions,i.e.,battery,superconductor,topological material,and artificial intelligence(AI)in materials science.The trained NLP‘battery’model applied on a larger dataset different from the training and testing dataset can achieve F1 score of 0.738,which indicates the accuracy and reliability of this scheme.Furthermore,our approach demonstrates that even with insufficient data,the not-well-trained model in the first few cycles can identify the relationships among different research fields and facilitate the discovery and understanding of interdisciplinary directions. 展开更多
关键词 natural language processing text mining materials science
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