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Superconductivity and pseudogap features of an isolated FeAs layer in KCa_(2)Fe_(4)As_(4)F_(2) unraveled by STM/STS

Science China(Physics,Mechanics & Astronomy) 2023年第8期66卷 131-138页

作者： Shuai Shao Fan zhang zongyuan zhang Teng Wang Yanwei Wu Yubing Tu Jie Hou Xingyuan Hou Ning Hao Gang Mu Lei Shan Information Materials and Intelligent Sensing Laboratory of Anhui Province Institutes of Physical Science and Information TechnologyAnhui UniversityHefei 230601China Key Laboratory of Structure and Functional Regulation of Hybrid Materials(Anhui University) Ministry of EducationHefei 230601China Beijing National Laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesBeijing 100190China State Key Laboratory of Functional Materials for Informatics Shanghai Institute of Microsystem and Information TechnologyChinese Academy of SciencesShanghai 200050China Anhui Key Laboratory of Condensed Matter Physics at Extreme Conditions High Magnetic Field Laboratory Hefei Institutes of Physical Science(HFIPS)Chinese Academy of SciencesUniversity of Science and Technology of ChinaHefei 230031China

To reveal the intrinsic properties of the basic superconducting units,i.e.,the single layered FeSe/FeAs in iron-based superconductors or CuO_(2) planes in cuprate superconductors,is a necessary prerequisite for understanding the mechanism of high-Tc *** to now,an isolated FeAs layer has rarely been studied due to the difficulty in materials ***,we report a scanning tunneling microscopy/spectroscopy(STM/STS)study on the iron-based superconductor KCa_(2)Fe_(4)As_(4)F_(2).In situ cleavage produced a single FeAs layer covered by a reconstructed K surface,which is isolated from the bulk by the underlying CaF layer and shows multi-band superconductivity with a much lower T_(c) than its bulk *** the exposed As-terminated regions with coverage of scattered K atoms,a pseudogap was observed,leading to an inhomogeneous superconductivity without long-range phase coherence in real space,which is remarkably similar to the high-T_(c) cuprate *** results provide a new perspective to understanding the origin of superconductivity in iron-based superconductors.

关键词： iron-based superconductor two-dimensional properties electronic correlation carrier doping scanning tunneling microscopy/spectroscopy

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Scanning tunneling microscopic observation of enhanced superconductivity in epitaxial Sn islands grown on SrTiO3 substrate

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Science Bulletin 2018年第20期63卷 1332-1337页

作者： Zhibin Shao zongyuan zhang Hui Yuan Haigen Sun Yan Cao Xin zhang Shaojian Li Habakubaho Gedeon Tao Xiang Qi-Kun Xue Minghu Pan School of Physics Huazhong University of Science and TechnologyWuhan 430074China Institute of Physics Chinese Academy of ScienceBeifing 100190China Collaborative Innovation Center of Quantum Matter Beijing 100084China State Key Laboratory of Low-Dimensional Quantum Physics Tsinghua UniversityBejiing 100084China

Recent experimental and theoretical studies of single-layer FeSe film grown on SrTiO_3 have revealed interface enhanced superconductivity, which opens up a pathway to promote the superconducting transition temperature. Here, to investigate the role of SrTiO_3 substrate in epitaxial superconducting film, we grew a conventional superconductor b-Sn(bulk T_c～ 3.72 K) onto SrTiO_3 substrate by molecular beam epitaxy. By employing scanning tunneling microscope and spectroscopic measurements, an enhanced Tcof 8.2 K is found for epitaxial b-Sn islands, deduced by fitting the temperature dependence of the gap values using the BCS formula. The observed interfacial charge injection and enhanced electron–phonon coupling are responsible for this Tcenhancement. Moreover, the critical field of 8.3 T exhibits a tremendous increase due to the suppression of the vortex formation. Therefore, the coexistence of enhanced superconductivity and high critical field of Sn islands demonstrates a feasible and effective route to improve the superconductivity by growing the islands of conventional superconductors on perovskite-type titanium oxide substrates.

关键词： Sn islands/SrTiO3 Interface-enhanced superconductivity Molecular beam epitaxy Scanning tunneling microscope Scanning tunneling spectroscopy

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Superconductivity and pseudogap features of an isolated FeAs layer in KCaFeAsFunraveled by STM/STS

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Science China(Physics,Mechanics & Astronomy) 2023年

作者： Shuai Shao Fan zhang zongyuan zhang Teng Wang Yanwei Wu Yubing Tu Jie Hou Xingyuan Hou Ning Hao Gang Mu Lei Shan Anhui Key Laboratory of Condensed Matter Physics at Extreme Conditions High Magnetic Field Laboratory Hefei Institutes of Physical Science (HFIPS) Chinese Academy of Sciences University of Science and Technology of China Information Materials and Intelligent Sensing Laboratory of Anhui Province Institutes of Physical Science and Information TechnologyAnhui University State Key Laboratory of Functional Materials for Informatics Shanghai Institute of Microsystem and Information Technology Chinese Academy of Sciences Beijing National Laboratory for Condensed Matter Physics Institute of Physics Chinese Academy of Sciences Key Laboratory of Structure and Functional Regulation of Hybrid Materials (Anhui University) Ministry of Education

To reveal the intrinsic properties of the basic superconducting units, i.e., the single layered FeSe/FeAs in iron-based superconductors or CuO2planes in cuprate superconductors, is a necessary prerequisite for understanding the mechanism of high-Tcsuperconductivity. Up to now, an isolated FeAs layer has rarely been studied due to the difficulty in materials synthesis. Here, we report a scanning tunneling microscopy/spectroscopy(STM/STS) study on the iron-based superconductor KCa2Fe4As4F2. In situ cleavage produced a single FeAs layer covered by a reconstructed K surface, which is isolated from the bulk by the underlying CaF layer and shows multi-band superconductivity with a much lower Tcthan its bulk counterpart. In the exposed As-terminated regions with coverage of scattered K atoms, a pseudogap was observed, leading to an inhomogeneous superconductivity without long-range phase coherence in real space, which is remarkably similar to the high-Tccuprate superconductors. These results provide a new perspective to understanding the origin of superconductivity in iron-based superconductors.

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Revisit of the anisotropic vortex states of 2H-NbSe_(2) towards the zero-field limit

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Chinese Physics B 2024年第6期33卷 80-86页

作者：张凡侯兴元姜宇轩张宗源涂玉兵朱相德陈根富单磊 Beijing National Laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesBeijing 100190China School of Physical Sciences University of Chinese Academy of SciencesBeijing 100190China Center of Free Electron Laser and High Magnetic Field Anhui UniversityHefei 230601China Information Materials and Intelligent Sensing Laboratory of Anhui Province Institutes of Physical Science and Information TechnologyAnhui UniversityHefei 230601China Key Laboratory of Structure and Functional Regulation of Hybrid Materials in Anhui University Ministry of EducationHefei 230601China School of Physics and Materials Science Anhui UniversityHefei 230601China Anhui Key Laboratory of Condensed Matter Physics at Extreme Conditions High Magnetic Field LaboratoryHFIPSAnhuiChinese Academy of Sciencesand University of Science and Technology of ChinaHefei 230031China Hefei National Laboratory Hefei 230088China

We revisited the vortex states of 2H-NbSe_(2) towards zero fields by a low-temperature scanning tunneling *** structures of the anisotropic vortex states were distinguished, one is a spatially non-splitting zero bias peak, and the other is an in-gap conductance anomaly resembling evolved crossing features around the center of the three nearest *** of them distribute solely along the next nearest neighboring direction of the vortex lattice and become unresolved in much higher magnetic fields, implying an important role played by the vortex–vortex interactions. To clarify these issues,we have studied the intrinsic vortex states of the isolated trapped vortex in zero fields at 0.45 K. It is concluded that the anisotropic zero bias peak is attributed to the superconducting gap anisotropy, and the spatially evolved crossing features are related to the vortex–vortex interaction. The vortex core size under the zero-field limit is determined. These results provide a paradigm for studying the inherent vortex states of type-II superconductors especially based on an isolated vortex.

关键词： vortex states zero-bias conductance peak scanning tunneling microscopy

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组蛋白乙酰化对灵芝生长、灵芝多糖和灵芝酸生物合成的影响

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中国农业科学 2020年第3期53卷 632-641页

作者：张宗源蒋咏梅章文贤福建师范大学生命科学学院河南省科学院生物研究所有限责任公司

【目的】组蛋白乙酰化修饰对真菌生长发育和次级代谢合成具有重要的调控作用。研究组蛋白乙酰化对静置培养的灵芝生长发育和主要代谢物合成的影响,为表观遗传手段提高灵芝多糖和灵芝酸生物合成提供理论依据。【方法】采用液体振荡-静置... 详细信息

【目的】组蛋白乙酰化修饰对真菌生长发育和次级代谢合成具有重要的调控作用。研究组蛋白乙酰化对静置培养的灵芝生长发育和主要代谢物合成的影响,为表观遗传手段提高灵芝多糖和灵芝酸生物合成提供理论依据。【方法】采用液体振荡-静置两阶段法培养灵芝。在静置培养阶段添加不同浓度(0、0.6、60、120和180μmol·L)辛二酰苯胺异羟肟酸(SAHA),采用常规方法测定或观察灵芝生物量、糖消耗、上层菌丝膜形成、菌丝体形态、灵芝孢子生成以及灵芝酸和灵芝多糖生物合成,利用蛋白免疫印迹技术测定灵芝组蛋白乙酰化水平;利用qRT-PCR技术对灵芝多糖(ugp、gls和pgm)、灵芝酸(hmgr、sqs、se和ls)生物合成关键基因以及灵芝全局调控因子相关基因(vet和LaeA)进行表达分析。【结果】SAHA处理使灵芝组蛋白H乙酰化水平提高,最高为对照组的1.6倍;抑制了灵芝菌丝体生长和色素产生,改变了菌丝体的形态。灵芝孢子的形成也受到抑制,且SAHA浓度越大,抑制程度越明显。SAHA处理显著增加了灵芝多糖的产量,最高增加50%;灵芝酸生物合成受到抑制,与对照相比降低13%—27%;qRT-PCR分析结果表明SAHA处理下灵芝多糖与灵芝酸合成关键酶基因表达均有不同程度上调,其中灵芝多糖合成关键酶基因提升1.5—3.5倍,灵芝酸合成关键酶基因提升1.8—12.1倍;灵芝全局性调控因子vet和LaeA的表达被抑制,仅为对照组的11.30%—62.4%。【结论】组蛋白乙酰化可通过灵芝全局调控因子调控灵芝生长发育进而影响灵芝酸生物合成,同时组蛋白乙酰化对灵芝多糖生物合也有影响。

关键词：灵芝组蛋白乙酰化灵芝酸灵芝多糖 SAHA

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Band engineering of valleytronics WSe_(2)–MoS_(2)heterostructures via stacking form,magnetic moment and thickness

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Chinese Physics B 2023年第10期32卷 45-49页

作者：吴彦玮张宗源马亮刘涛郝宁吕文刚龙明生单磊 Information Materials and Intelligent Sensing Laboratory of Anhui Province Key Laboratory of Structure and Functional Regulation of Hybrid Materials of Ministry of EducationInstitutes of Physical Science and Information TechnologyAnhui UniversityHefei 230601China State Key Laboratory of Metastable Materials Science&Technology and Key Laboratory for Microstructural Material Physics of Hebei Province School of ScienceYanshan UniversityQinhuangdao 066004China Anhui Province Key Laboratory of Condensed Matter Physics at Extreme Conditions High Magnetic Field LaboratoryChinese Academy of SciencesHefei 230031China Beijing National center for Condensed Matter Physics Beijing Key Laboratory for Nanomaterials and NanodevicesInstitute of PhysicsChinese Academy of SciencesBeijing 100190China

Spin-valley polarization and bandgap regulation are critical in the developing of quantum ***,by employing the density functional theory,we investigate the effects of stacking form,thickness and magnetic moment in the electronic structures of WSe_(2)–MoS_(2)*** show that spin-valley polarization maintains in all *** thickness of 2H-MoS_(2)not only tunes the bandgap but also changes the degeneracy of the conduction band minimums(CBM)at K/K_(1) *** increase of micro magnetic moment tunes the bandgap and raises the valence band maximums(VBM)atΓ*** addition,the regulation of band gap by the thickness of 2H-MoS_(2)and introduced magnetic moment depends on the stacking *** suggest that WSe_(2)–MoS_(2)heterostructure supports an ideal platform for valleytronics *** methods also give new ways of optical absorption regulation in spin-valley devices.

关键词： valleytronics thickness stacking magnetic moment

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土壤中游离烃技术的油气化探意义

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天然气工业 2004年第6期24卷 30-32,i001页

作者：张宗元王国建中国石化勘探开发研究院石油化探研究所

介绍了游离烃技术方法 ,该方法通过抽取土壤中气体 ,检测其中与油气微渗漏有关的烃类组分 ,确定油气化探异常。研究了游离烃组分的浓度分布特征 ,揭示出烷烃中甲烷 (以YC1 表示 )是独立因子 ,加之其浓度分布分异性好 ,证明了YC1 中储存... 详细信息

介绍了游离烃技术方法 ,该方法通过抽取土壤中气体 ,检测其中与油气微渗漏有关的烃类组分 ,确定油气化探异常。研究了游离烃组分的浓度分布特征 ,揭示出烷烃中甲烷 (以YC1 表示 )是独立因子 ,加之其浓度分布分异性好 ,证明了YC1 中储存与油气有关的信息 ,具有重要的化探意义。通过游离烃组分与其它化探指标关系的分析研究 ,得出了与其它化探指标不相关的认识 ,证明游离烃在其它化探指标中是独立因子 ,指出其具有独立的化探意义。最后阐述了其化探意义表现的 3个方面 :已知区验证效果良好 ;应用地域广阔 ,不仅适用于北方碱性土壤区 ,更适用于南方酸性土壤区 ;YC1 的δ1 3C1 具有良好的应用前景。

关键词：土壤游离烃技术甲烷地球化学勘探油气勘探酸解烃

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胜利油田火烧油层先导性试验研究

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石油钻采工艺 1996年第3期18卷 88-92页

作者：张宗源谢志勤胜利石油管理局采油工艺研究院

火烧油层是国内外热力开采稠油的有效方法之一。本文简述了胜利油田火烧油层先导试验室内研究、火烧工艺装备技术、现场试验、存在问题及认识。胜利油田火烧油层先导性试验研究，为火驱法开采稠油提供了借鉴。

关键词：油田火烧油层先导试验燃烧前缘动态监测

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平衡式行星传动齿轮泵不同压油方式动态特性

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机床与液压 2014年第19期42卷 1-4页

作者：张宗元赵升吨西安交通大学机械工程学院陕西西安710049

介绍了传统齿轮泵存在的不足和齿轮泵的发展,提出了3种不同啮合方式的平衡式行星传动齿轮泵:平衡式外啮合多齿轮泵、平衡式复合齿轮泵、平衡式内啮合多齿轮泵,并阐述了3种泵的工作原理。分析了3种不同啮合方式的平衡式行星传动齿轮泵的... 详细信息

介绍了传统齿轮泵存在的不足和齿轮泵的发展,提出了3种不同啮合方式的平衡式行星传动齿轮泵:平衡式外啮合多齿轮泵、平衡式复合齿轮泵、平衡式内啮合多齿轮泵,并阐述了3种泵的工作原理。分析了3种不同啮合方式的平衡式行星传动齿轮泵的流量特性与力学特性,指出平衡式行星传动齿轮泵从结构上解决了齿轮泵液压径向力不平衡的问题,并在大大增大齿轮泵的排量的同时,减小了齿轮泵的流量脉动,指出了平衡式行星传动齿轮泵是齿轮泵未来的发展方向。

关键词：平衡式行星传动齿轮泵流量脉动径向液压力

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Superconducting state in Ba_((1-x)) Sr_(x)Ni_(2)As_(2) near the quantum critical point

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Chinese Physics B 2024年第6期33卷 488-493页

作者：余承峰张宗源宋林兴吴彦玮袁小秋侯杰涂玉兵侯兴元李世亮单磊 Information Materials and Intelligent Sensing Laboratory of Anhui Province Institutes of Physical Science and Information TechnologyAnhui UniversityHefei 230601China Key Laboratory of Structure and Functional Regulation of Hybrid Materials(Anhui University) Ministry of EducationHefei 230601China Beijing National Laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesBeijing 100190China School of Physical Sciences University of Chinese Academy of SciencesBeijing 100190China Songshan Lake Materials Laboratory Dongguan 523808China

In the phase diagram of the nickel-based superconductor Ba_(1-x)Sr_(x)Ni_(2)As_(2),T_(C) has been found to be enhanced sixfold near the quantum critical point(QCP) x=0.71 compared with the parent ***,the mechanism is still under ***,we report a detailed investigation of the superconducting properties near the QCP(x≈0.7) by utilizing scanning tunneling microscopy and *** temperature-dependent superconducting gap and magnetic vortex state were obtained and analyzed in the framework of the Bardeen-Cooper-Schrieffer *** ideal isotropic s-wave superconducting gap excludes the long-speculated nematic fluctuations while preferring strong electron-phonon coupling as the mechanism for T_(C) enhancement near the *** lower than expected gap ratio of Δ/(k_(B) T_(C)) is rooted in the fact that Ba_(1-x)Sr_(x)Ni_(2)As_(2) falls into the dirty limit with a serious pair breaking effect similar to the parent compound.

关键词： nickel-based superconductor electron–phonon coupling dirty limit scanning tunneling microscopy/spectroscopy

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