MEET in Beijing 2002, an international gala month, tookplace last May in China’s capital. The theme of this month-long festival was to "enjoy arts, beauty, hope, and the spring."
By measuring scanning tunneling spectroscopy on some large Bi islands deposited on FeTe_(0.55)Se_(0.45)superconductors,we observe clear in-gap edge states with double peaks at about±1.0 me V on the spectra measur...By measuring scanning tunneling spectroscopy on some large Bi islands deposited on FeTe_(0.55)Se_(0.45)superconductors,we observe clear in-gap edge states with double peaks at about±1.0 me V on the spectra measured near the perimeter of the islands.This feature is very different from the single zero-energy peak observed on some other small Bi islands.The edge states spread towards the inner side of the islands over a width of 2-3 nm.The two edge-state peaks at positive and negative energies move to higher values with the increase of the magnetic field,and they disappear near the transition temperature of FeTe_(0.55)Se_(0.45).Meanwhile,enhanced superconducting gaps are observed in the central regions of these Bi islands,which may be induced by the enhanced pair potential of the topological surface state.Our observations provide a valuable message for the edge state and the proximity-induced superconductivity on specific Bi islands grown on FeTe_(0.55)Se_(0.45)substrate.展开更多
Interface can be a fertile ground for exotic quantum states,including topological superconductivity,Majorana mode,fractal quantum Hall effect,unconventional superconductivity,Mott insulator,etc.Here we grow single-uni...Interface can be a fertile ground for exotic quantum states,including topological superconductivity,Majorana mode,fractal quantum Hall effect,unconventional superconductivity,Mott insulator,etc.Here we grow single-unit-cell(1UC)FeTe film on NbSe_(2)single crystal by molecular beam epitaxy(MBE)and investigate the film in-situ with a home-made cryogenic scanning tunneling microscopy(STM)and non-contact atomic force microscopy(AFM)combined system.We find different stripe-like superlattice modulations on grown FeTe film with different misorientation angles with respect to NbSe_(2)substrate.We show that these stripe-like superlattice modulations can be understood as moirépattern forming between FeTe film and NbSe_(2)substrate.Our results indicate that the interface between Fe Te and NbSe2 is atomically sharp.By STM-AFM combined measurement,we suggest that the moirésuperlattice modulations have an electronic origin when the misorientation angle is relatively small(≤3°)and have structural relaxation when the misorientation angle is relatively large(≥10°).展开更多
Majorana fermions have been predicted to exist at the edge states of a two-dimensional topological superconductor.We fabricated single quintuple layer(QL)Bi2Te3/FeTe heterostructure with the step-flow epitaxy method a...Majorana fermions have been predicted to exist at the edge states of a two-dimensional topological superconductor.We fabricated single quintuple layer(QL)Bi2Te3/FeTe heterostructure with the step-flow epitaxy method and studied the topological properties of this system by using angle-resolved photoemission spectroscopy and scanning tunneling microscopy/spectroscopy.We observed the coexistence of robust superconductivity and edge states on the single QL Bi2Te3 islands which can be potential evidence for topological superconductor.展开更多
Chenguodaite, approved by IMA-CNMMN (2004-042a), was discovered in the Bunan quartz vein-type gold deposit in the gold district of East Shandong Peninsula. The mineral occurs in high grade Au-Ag-Cu ores, coexisting wi...Chenguodaite, approved by IMA-CNMMN (2004-042a), was discovered in the Bunan quartz vein-type gold deposit in the gold district of East Shandong Peninsula. The mineral occurs in high grade Au-Ag-Cu ores, coexisting with galena, chalcopyrite, hessite, electrum, unnamed Ag6TeS2 and Ag16FeBiTe3S8, enclosed and replaced by native silver and acanthite. In the reflected light microscope, the mineral has light gray color, indistinguishable anistropism and hardness around 2―3. The color indices of chenguodaite relative to ICE C illuminator are: x=0.3027, y=0.3076, Y=25.78%, λd=474 nm, Pe=3.68%, similar to those of canfieldite. The average chemical composition from 16 microprobe analyses is Ag8.97Fe1.00Te1.99S4.04, idealized to Ag9FeTe2S4. The polycrystalline X-ray diffraction of chenguodaite by Gandolfi camera and synchrotron oscillation photography results in 67 reflections with the 12 strongest being (relative intensity in bracket): 6.742(69), 6.416(39), 5.951(33), 3.265(100), 2.981(24), 2.649(22), 2.25(24), 2.188(71), 2.142(22), 2.123(31), 2.044(23), 1.949(33), which are indexed to a primitive orthorhombic cell with a=12.769 (2) , b= 14.814(2), c= 16.233 (1) , V= 3070.63, Z = 9, Dcal.=6.85 g/cm3. The name is for the late Prof. Chen Guoda, a famous Chinese geologist and the founder of Diwa-Geodepression theory of tectonics.展开更多
The remarkable advantages of heterojunction engineering have injected significant vitality into the design of high-performance electromagnetic wave absorption(EWA)materials.Understanding interface effects,rather than ...The remarkable advantages of heterojunction engineering have injected significant vitality into the design of high-performance electromagnetic wave absorption(EWA)materials.Understanding interface effects,rather than semiempirical rules,can facilitate the rational design of heterostructures,thereby enabling effective modulation of impedance matching and the EWA properties of materials.Herein,FeTe@expanded graphite(FeTe@EG)heterostructures are in-situ constructed via a one-step chemical vapor deposition(CVD)method,which effectively generates abundant Mott–Schottky heterojunctions and exhibit a strong built-in electric field(BIEF)effect.The optimal sample,featuring only 10 wt.%filler content and a thickness of 1.8 mm,achieved an effective absorption bandwidth(EAB)of 4.6 GHz and a minimum reflection loss(RLmin)of−63.8 dB.Density functional theory(DFT)calculations and finite element simulations demonstrate that the BIEF effectively modulates charge separation,promotes electron migration,and ultimately improves polarization relaxation loss,leading to superior EWA performance.This study elucidates the intrinsic mechanism by which the FeTe-based heterojunction couples with polarization responses,providing a feasible strategy for the design of lightweight,efficient,and high-performance electromagnetic wave absorbers based on other high-density transition metal telluride(TMT)materials.展开更多
文摘MEET in Beijing 2002, an international gala month, tookplace last May in China’s capital. The theme of this month-long festival was to "enjoy arts, beauty, hope, and the spring."
基金supported by the National Key R&D Program of China(Grant Nos.2022YFA1403201 and 2024YFA1408104)the National Natural Science Foundation of China(Grant Nos.11927809 and 12434004)the Natural Science Foundation of Jiangsu Province(Grant No.BK20233001)。
文摘By measuring scanning tunneling spectroscopy on some large Bi islands deposited on FeTe_(0.55)Se_(0.45)superconductors,we observe clear in-gap edge states with double peaks at about±1.0 me V on the spectra measured near the perimeter of the islands.This feature is very different from the single zero-energy peak observed on some other small Bi islands.The edge states spread towards the inner side of the islands over a width of 2-3 nm.The two edge-state peaks at positive and negative energies move to higher values with the increase of the magnetic field,and they disappear near the transition temperature of FeTe_(0.55)Se_(0.45).Meanwhile,enhanced superconducting gaps are observed in the central regions of these Bi islands,which may be induced by the enhanced pair potential of the topological surface state.Our observations provide a valuable message for the edge state and the proximity-induced superconductivity on specific Bi islands grown on FeTe_(0.55)Se_(0.45)substrate.
基金Project supported by the National Key Research and Development Program of China(Grant Nos.2016YFA0302400,2016YFA0300602,and2017YFA0302903)the National Natural Science Foundation of China(Grant No.11227903)+2 种基金the Beijing Municipal Science and Technology Commission,China(Grant Nos.Z181100004218007 and Z191100007219011)the National Basic Research Program of China(Grant No.2015CB921304)the Strategic Priority Research Program of Chinese Academy of Sciences(Grant Nos.XDB07000000,XDB28000000,and XDB33000000)。
文摘Interface can be a fertile ground for exotic quantum states,including topological superconductivity,Majorana mode,fractal quantum Hall effect,unconventional superconductivity,Mott insulator,etc.Here we grow single-unit-cell(1UC)FeTe film on NbSe_(2)single crystal by molecular beam epitaxy(MBE)and investigate the film in-situ with a home-made cryogenic scanning tunneling microscopy(STM)and non-contact atomic force microscopy(AFM)combined system.We find different stripe-like superlattice modulations on grown FeTe film with different misorientation angles with respect to NbSe_(2)substrate.We show that these stripe-like superlattice modulations can be understood as moirépattern forming between FeTe film and NbSe_(2)substrate.Our results indicate that the interface between Fe Te and NbSe2 is atomically sharp.By STM-AFM combined measurement,we suggest that the moirésuperlattice modulations have an electronic origin when the misorientation angle is relatively small(≤3°)and have structural relaxation when the misorientation angle is relatively large(≥10°).
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61734008 and 11774143)the National Key Research and Development Program of China(Grant Nos.2018YFA0307100,2016YFA0301703,and 2016YFA0300300)+4 种基金the Natural Science Foundation of Guangdong Province,China(Grant Nos.2015A030313840 and 2017A030313033)the State Key Laboratory of Low-Dimensional Quantum Physics(Grant No.KF201602)Technology and Innovation Commission of Shenzhen Municipality,China(Grant Nos.ZDSYS20170303165926217 and JCYJ20170412152334605)Guangdong Provincial Key Laboratory,China(Grant No.2019B121203002)J.-W.M.was partially supported by the Program for Guangdong Introducing Innovative and Entrepreneurial Teams,China(Grant No.2017ZT07C062).
文摘Majorana fermions have been predicted to exist at the edge states of a two-dimensional topological superconductor.We fabricated single quintuple layer(QL)Bi2Te3/FeTe heterostructure with the step-flow epitaxy method and studied the topological properties of this system by using angle-resolved photoemission spectroscopy and scanning tunneling microscopy/spectroscopy.We observed the coexistence of robust superconductivity and edge states on the single QL Bi2Te3 islands which can be potential evidence for topological superconductor.
文摘利用固态反应法制备了名义成分为FeTe的合金,采用X射线粉末衍射技术和Rietveld全谱拟合分析方法测定了其相组成和晶体结构.研究表明,主相为。Fe_l.08Te,空间群为P4/nmm,点阵参数a=3.8214(3)A,c=6.2875(3)A,z=2,Fe原子占据2a和2c晶位,Te原子占据2c晶位.利用脉冲激光沉积技术制备的FeTe薄膜超导转变起始温度为13.2 K,零电阻温度为9.8 K.
基金National Natural Science Foundation of China (Grant No. 40572027)
文摘Chenguodaite, approved by IMA-CNMMN (2004-042a), was discovered in the Bunan quartz vein-type gold deposit in the gold district of East Shandong Peninsula. The mineral occurs in high grade Au-Ag-Cu ores, coexisting with galena, chalcopyrite, hessite, electrum, unnamed Ag6TeS2 and Ag16FeBiTe3S8, enclosed and replaced by native silver and acanthite. In the reflected light microscope, the mineral has light gray color, indistinguishable anistropism and hardness around 2―3. The color indices of chenguodaite relative to ICE C illuminator are: x=0.3027, y=0.3076, Y=25.78%, λd=474 nm, Pe=3.68%, similar to those of canfieldite. The average chemical composition from 16 microprobe analyses is Ag8.97Fe1.00Te1.99S4.04, idealized to Ag9FeTe2S4. The polycrystalline X-ray diffraction of chenguodaite by Gandolfi camera and synchrotron oscillation photography results in 67 reflections with the 12 strongest being (relative intensity in bracket): 6.742(69), 6.416(39), 5.951(33), 3.265(100), 2.981(24), 2.649(22), 2.25(24), 2.188(71), 2.142(22), 2.123(31), 2.044(23), 1.949(33), which are indexed to a primitive orthorhombic cell with a=12.769 (2) , b= 14.814(2), c= 16.233 (1) , V= 3070.63, Z = 9, Dcal.=6.85 g/cm3. The name is for the late Prof. Chen Guoda, a famous Chinese geologist and the founder of Diwa-Geodepression theory of tectonics.
基金supported by the National Natural Science Foundation of China(Nos.62174013,92265111,52273279,and W2412065)the Beijing Natural Science Foundation(Nos.JQ23007 and L233003)。
文摘The remarkable advantages of heterojunction engineering have injected significant vitality into the design of high-performance electromagnetic wave absorption(EWA)materials.Understanding interface effects,rather than semiempirical rules,can facilitate the rational design of heterostructures,thereby enabling effective modulation of impedance matching and the EWA properties of materials.Herein,FeTe@expanded graphite(FeTe@EG)heterostructures are in-situ constructed via a one-step chemical vapor deposition(CVD)method,which effectively generates abundant Mott–Schottky heterojunctions and exhibit a strong built-in electric field(BIEF)effect.The optimal sample,featuring only 10 wt.%filler content and a thickness of 1.8 mm,achieved an effective absorption bandwidth(EAB)of 4.6 GHz and a minimum reflection loss(RLmin)of−63.8 dB.Density functional theory(DFT)calculations and finite element simulations demonstrate that the BIEF effectively modulates charge separation,promotes electron migration,and ultimately improves polarization relaxation loss,leading to superior EWA performance.This study elucidates the intrinsic mechanism by which the FeTe-based heterojunction couples with polarization responses,providing a feasible strategy for the design of lightweight,efficient,and high-performance electromagnetic wave absorbers based on other high-density transition metal telluride(TMT)materials.
