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Kagome superconductors AV3Sb5(A = K, Rb, Cs)

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National Science Review 2023年第2期10卷 260-275页

作者： Kun Jiang Tao Wu Jia-Xin Yin Zhenyu Wang M.Zahid Hasan stephen D.wilson Xianhui Chen Jiangping Hu Beijing National Laboratory for Condensed Matter Physics and Institute of Physics Chinese Academy of Sciences School of Physical Sciences University of Chinese Academy of Sciences Hefei National Laboratory for Physical Sciences at the Microscale University of Science and Technology of China CAS Key Laboratory of Strongly-coupled Quantum Matter Physics Department of Physics University of Science and Technology of China Laboratory for Quantum Emergence Department of PhysicsSouthern University of Science and Technology Laboratory for Topological Quantum Matter and Advanced Spectroscopy (B7) Department of PhysicsPrinceton University Materials Department and California Nanosystems Institute University of California Santa Barbara Kavli Institute of Theoretical Sciences University of Chinese Academy of Sciences

The quasi-two-dimensional kagome materials AV3Sb5(A=K,Rb,Cs) were found to be a prime example of kagome superconductors,a new quantum platform to investigate the interplay between electron correlation effects,topology and geometric *** this review,we report recent progress on the experimental and theoretical studies of AV3Sb5and provide a broad picture of this fast-developing field in order to stimulate an expanded search for unconventional kagome *** review the electronic properties of AV3Sb5,the experimental measurements of the charge density wave state,evidence of time-reversal symmetry breaking and other potential hidden symmetry breaking in these materials.A variety of theoretical proposals and models that address the nature of the time-reversal symmetry breaking are ***,we review the superconducting properties of AV3Sb5,especially the potential pairing symmetries and the interplay between superconductivity and the charge density wave state.

关键词： kagome superconductor charge density wave time-reversal symmetry breaking topological metal

Anomalous CDW ground state in Cu_(2)Se:A wave-like fluctuation of the dc I-v curve near 50 K

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Journal of Materiomics 2017年第2期3卷 150-157页

作者： Mengliang Yao Weishu Liu Xiang Chen Zhensong Ren stephen wilson Zhifeng Ren Cyril P.Opeil Department of Physics Boston CollegeChestnut HillMA 02467USA Department of Physics and TcSUH University of HoustonTX 77204USA Department of Materials University of CaliforniaSanta BarbaraCA 93106USA Department of Materials Science and Engineering Southern University of Science and TechnologyShenzhenGuangdong 518055China

A charge density wave(CDW)ground state is observed in polycrystalline Cu_(2)Se below 125 K,which corresponds to an energy gap of 40.9 meV and an electron-phonon coupling constant of *** to the polycrystalline structure,the Peierls transition process has been expanded to a wide temperature range from 90 K to 160 *** Hall carrier concentration shows a continuous decrease from 2.1×10^(20)to 1.6×10^(20)cm^(-3)in the temperature range from 160 K to 90 K,while almost unchanged above 160 K and below 90 *** entering the CDW ground state,a wave-like fluctuation was observed in theI-Vcurve near 50 K,which exhibits a periodic negative differential resistivity in an applied electric field due to the *** also investigated the doping effect of Zn,Ni,and Te on the CDWground *** Zn and Ni doped Cu_(2)Se show a CDW character with increased energy gap and electron-phonon coupling constant,but no notable Peierls transition was observed in Te doped Cu_(2)*** wave-likeI-Vcurve was also seen in Cu_(1.98)Zn_(0.02)Se near 40 *** regular fluctuation in the dcI-Vcurve was not magnetic field sensitive,but temperature and sample size sensitive.

关键词： Peierls transition CDW dc I-V curve Wave-like fluctuation Copper selenide

Biotyping of Multidrug Resistant <i>Campylobacter jejuni</i>from Poultry and Humans in Northern Region of Ghana

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Open Journal of Medical Microbiology 2021年第1期11卷 18-31页

作者： Akosua Bonsu Karikari Courage Kosi Setsoafia Saba stephen wilson Kpordze Department of Clinical Microbiology School of Medicine and Health Sciences University for Development Studies P. O. Box TL 1350 Tamale Ghana Department of Biotechnology Faculty of Agriculture University for Development Studies P. O. Box TL 1882 Tamale Ghana

Thermophilic Campylobacters are zoonotic bacteria which are universally famous for causing enteritis in humans. They are normally found as commensals in the digestive tract of food animals with poultry being a major reservoir of the pathogenic species. This study highlighted the presence of Campylobacter in poultry (commercial and domestic) and humans (patients and asymptomatic individuals) and characterized strains by biotyping and susceptibility test in the Northern region of Ghana where animal husbandry is commonly practiced but zoonotic studies are limited. A total of 1087 specimens from stools of humans and cloacal swabs of poultry were screened from 25th October, 2017 to 7th May, 2019. Samples were cultured on modified charcoal-cefoperazone-deoxycholate agar and isolates identified using standard microbiological procedures and Lior Biotyping, while the antibiogram of isolates was determined by the Kirby-Bauer disk diffusion method. The frequency of Campylobacter was 43.1% and 12.9% respectively in poultry and humans. Campylobacter jejuni were recovered from 84% of commercial birds and 64% of domestic birds and in humans significantly fewer strains were observed in patients than asymptomatic individuals (p <

关键词： Campylobacter Antibiotic Resistance Multidrug Resistance Biotyping Ghana

Development and application of a system for the analysis of atmospheric, water and sediment nitrogen and carbon

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Journal of Environmental Science and Engineering 2009年第9期3卷 35-49页

作者： Ann Stavert stephen R. wilson Dianne F. Jolley School of Chemistry University of Wollongong NSW 2522 Australia CSIRO Marine and Atmospheric Research PB 1 Aspendale Vic 3195 Australia

Eutrophication and climate change, key environmental concerns, are both linked to the carbon and nitrogen cycles hence the improved understanding of these cycles is essential. Currently, there is no system that simultaneously measures the fluxes of the three key gas phase products of nitrogen and carbon cycling （CO2, CH4 and N2O） in submerged ecosystems with hourly time resolution. A ＂Lake-in-a-box＂（mesocosm） was developed in the laboratory which allowed the monitoring of key components of the carbon and nitrogen cycles within the air, water and sediments. The approach is automated, simple and time efficient and novel in its ability to examine many different carbon and nitrogen compounds in all three physical component of the ＂lake＂. Dramatic fluctuations in gaseous flux and the concentrations of overlying water and sedimentary carbon and nitrogen compounds were noted over a three week period. These were split into five distinct phases which were linked to changes in sedimentary N and C cycling. The results highlighted the important of links between the two cycles and supported recent studies showing that estuarine sediments can act as both a source and a sink of nitrogen.

关键词： nitrogen cycle carbon cycle monitoring systems estuarine chemistry gas production Australia New South Wales Lake Macquarie

Nodeless superconductivity in the kagome metal CsV3Sb5

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Science China(Physics,Mechanics & Astronomy) 2021年第10期64卷 19-24页

作者： Weiyin Duan Zhiyong Nie Shuaishuai Luo Fanghang Yu Brenden R.Ortiz Lichang Yin Hang Su Feng Du An Wang Ye Chen Xin Lu Jianjun Ying stephen D.wilson Xianhui Chen Yu Song Huiqiu Yuan Center for Correlated Matter and Department of Physics Zhejiang University Zhejiang Province Key Laboratory of Quantum Technology and Device Department of Physics Zhejiang University Hefei National Laboratory for Physical Sciences at Microscale and Department of Physics and CAS Key Laboratory of Strongly-coupled Quantum Matter Physics University of Science and Technology of China Materials Department and California Nanosystems Institute University of California Santa Barbara CAS Center for Excellence in Quantum Information and Quantum Physics Collaborative Innovation Center of Advanced Microstructures State Key Laboratory of Silicon Materials Zhejiang University

The recently discovered kagome metal series AV3Sb5(A=K, Rb, Cs) exhibits topologically nontrivial band structures, chiral charge order and superconductivity, presenting a unique platform for realizing exotic electronic states. The nature of the superconducting state and the corresponding pairing symmetry are key questions that demand experimental clarification. Here, using a technique based on the tunneling diode oscillator, the magnetic penetration depth ?λ(T) of CsV3Sb5was measured down to 0.07 K. A clear exponential behavior in ?λ(T) with marked deviations from a T or T2 temperature dependence was observed at low temperatures, indicating an absence of nodal quasiparticles. Temperature dependence of the superfiuid density and electronic specific heat can be described by two-gap s-wave superconductivity, consistent with the presence of multiple Fermi surfaces in CsV3Sb5. These results evidence nodeless superconductivity in CsV3Sb5under ambient pressure, and constrain the allowed pairing symmetry.

关键词： kagome superconductor order parameter penetration depth PACS number(s)74.25.-q 74.25.Bt 74.25.Ha 74.20.Rp

Surface-induced orbital-selective band reconstruction in kagome superconductor CsV_(3)Sb_(5)

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Chinese Physics B 2022年第5期31卷 10-14页

作者： Linwei Huai Yang Luo Samuel M.L.Teicher Brenden R.Ortiz Kaize Wang Shuting Peng Zhiyuan Wei Jianchang Shen Bingqian Wang Yu Miao Xiupeng Sun Zhipeng Ou stephen D.wilson Junfeng He CAS Key Laboratory of Strongly-coupled Quantum Matter Physics and Department of Physics University of Science and Technology of ChinaHefei 230026China Materials Department and California Nanosystems Institute University of California Santa BarbaraSanta BarbaraCalifornia 93106USA

The two-dimensional(2 D)kagome superconductor Cs V_(3)Sb_(5) has attracted much recent attention due to the coexistence of superconductivity,charge orders,topology and kagome physics,which manifest themselves as distinct electronic structures in both bulk and surface states of the *** interesting next step is to manipulate the electronic states in this ***,we report angle-resolved photoemission spectroscopy(ARPES)evidence for a surface-induced orbitalselective band reconstruction in Cs V_(3)Sb_(5).A significant energy shift of the electron-like band aroundΓand a moderate energy shift of the hole-like band around M are observed as a function of *** evolution is reproduced in a much shorter time scale by in-situ annealing of the Cs V_(3)Sb_(5) ***-resolved density functional theory(DFT)calculations reveal that the momentum-dependent band reconstruction is associated with different orbitals for the bands aroundΓand M,and the time-dependent evolution points to the change of sample surface that is likely caused by the formation of Cs vacancies on the *** results indicate the possibility of orbital-selective control of the band structure via surface modification,which may open a new avenue for manipulating exotic phenomena in this material system,including superconductivity.

关键词： photoemission kagome superconductor band structure

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“奥”林争霸，“金”落谁家——伦敦奥运夺金热门预测

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新东方英语(中学生) 2012年第7期 4-8页

作者： stephen wilson 赵青奇不详

伦敦奥运会眨眼将至,各国运动员蓄势待发,势要全力以赴、一展风采。在奥林匹克的各项争霸赛中,自有巨星光芒万丈,更有新星冉冉升起。或许每个人心中都有自己看好的"奥"林英雄,他们能否问鼎"奥"林,捧得金牌归?

关键词：菲尔普斯沃尔什博尔特奥运金牌杜兰特游泳运动员伦敦奥运足球比赛羽毛球出生日期北京奥运会

Topological surface states and flat bands in the kagome superconductor CsV_(3)Sb_(5)

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Science Bulletin 2022年第5期67卷 495-500,M0004页

作者： Yong Hu Samuel M.L.Teicher Brenden R.Ortiz Yang Luo Shuting Peng Linwei Huai Junzhang Ma Nicholas CPlumb stephen D.wilson Junfeng He Ming Shi Department of Physics and CAS Key Laboratory of Strongly-coupled Quantum Matter Physics University of Science and Technology of ChinaHefei 230026China Swiss Light Source Paul Scherrer InstituteVilligen PSI CH-5232Switzerland Materials Department and California Nanosystems Institute University of California Santa BarbaraSanta BarbaraCA93106USA Department of Physics City University of Hong KongHong KongChina

Exotic quantum phenomena may appear in material systems with multiple orders or phases,where the mutual interactions can give rise to new physics beyond that of each ***,we report spectroscopic evidence for a unique combination of topology and correlation effects in the kagome superconductor CsV_(3)Sb_(5).Topologically nontrivial surface states are observed near the Fermi energy(E_(F)),indicating that the topological physics may be active upon entering the superconducting *** bands are observed,suggesting that electron correlation effects are also at play in this *** results reveal the peculiar electronic structure of CsV_(3)Sb_(5),which holds the potential for realizing Majorana zero modes and anomalous superconducting states in kagome *** also establish CsV_(3)Sb_(5)as a unique platform for exploring the interactions between the charge order,topology,correlation effects and superconductivity.

关键词： ARPES Kagome superconductors Charge density wave order Topologically nontrivial surface states

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DEM investigation of strength and critical state behaviours of granular materials under true triaxial loadings

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Particuology 2024年第2期85卷 198-212页

作者： Minyi Zhu Guobin Gong Jun Xia stephen Wilkinson Department of Civil Engineering Xi'an Jiaotong-Liverpool UniversityChina Department of Civil Engineering and Industrial Design University of LiverpoolLiverpoolUK Faculty of Engineering and Information Sciences University of Wollongong in DubaiUnited Arab Emirates

This paper investigates the strength and critical state(CS)behaviours of granular materials via DEM simulations of true triaxial drained tests under three different loading modes including constant b(in-termediate stress ratio)tests with constantσ'1(major principal stress),constant p(mean pressure)and constantσ'3(minor principal stress)*** this end,a series of samples are generated with the same particle size distribution,and with the confining stresses ranging from 100 kPa to 900 *** CS is achieved for all *** the macroscopic behaviours and the microscopic behaviours are examined and compared considering different loading modes,confining stresses and intermediate stress ratios(b).The critical state lines(CSLs)are found to be unique and independent of the loading modes,but dependent on the b *** CSLs with b=0 and b=1 form the two boundaries of CSLs respectively beyond which CSLs under all other b tests cannot go *** different strength criteria are examined and compared in terms of both peak and CS *** Mohr-Coulomb strength criterion is found to be only suitable for axisymmetric loading *** Lade-Duncan criterion is only suitable for describing peak strengths,which is dependent on the loading modes and confining *** Satake criterion and Matsuoka-Nakai criterion are the more appropriate strength criteria for describing CS failures,indicating that the CS values of both the Satake parameter and the Matsuoka-Nakai parameter describe an inherent property that characterizes the CS failure for a given type of *** CS mechanical coordination number is fitted by a curved line for a given b value,which is unique regardless of the loading *** peak and CS values of both major and minor principal fabric tensors decrease with increasing b values,while they increase with increasing b values for the intermediate principal fabric tensor.

关键词： Discrete element method Intermediate stress ratio Dilation Critical state Failure criterion