A5011827650- Iron-based superconductors research
- Physics of Superconductivity and Magnetism
- Rare-earth and actinide compounds
- Corporate Taxation and Avoidance
- Topological Materials and Phenomena
- Intellectual Capital and Performance Analysis
- Advanced Condensed Matter Physics
- Superconductivity in MgB2 and Alloys
- Inorganic Chemistry and Materials
- Magnetic and transport properties of perovskites and related materials
- Electronic and Structural Properties of Oxides
- Quantum and electron transport phenomena
- 2D Materials and Applications
- Organic and Molecular Conductors Research
- Crystal Structures and Properties
- Surface and Thin Film Phenomena
- Chalcogenide Semiconductor Thin Films
- Molecular Junctions and Nanostructures
- Advanced Chemical Physics Studies
- Semiconductor Quantum Structures and Devices
- Surface Chemistry and Catalysis
- Inorganic Fluorides and Related Compounds
- Advanced Materials and Mechanics
- Advanced Physical and Chemical Molecular Interactions
- Acoustic Wave Resonator Technologies
University of Science and Technology of China
2011-2025
Jinan University
2025
Hefei National Center for Physical Sciences at Nanoscale
2009-2024
Shanghai Institute of Microsystem and Information Technology
2024
Chongqing University
2024
National Synchrotron Radiation Laboratory
2024
Shanghai Advanced Research Institute
2024
Fudan University
2010-2021
State Key Laboratory of Surface Physics
2015-2021
Collaborative Innovation Center of Advanced Microstructures
2015-2021
We report systematic optical studies of WS2 and WSe2 monolayers multilayers. The efficiency second harmonic generation shows a dramatic even-odd oscillation with the number layers, consistent presence (absence) inversion symmetry in even-layer (odd-layer). Photoluminescence (PL) measurements show crossover from an indirect band gap semiconductor at multilayers to direct-gap one monolayers. A hot luminescence peak (B) is observed ~0.4 eV above prominent edge (A) all samples. magnitude A-B...
The Majorana fermion, which is its own anti-particle and obeys non-abelian statistics, plays a critical role in topological quantum computing. It can be realized as bound state at zero energy, called mode (MZM), the vortex core of superconductor, or ends nanowire when both superconductivity strong spin orbital coupling are present. A MZM detected zero-bias conductance peak (ZBCP) tunneling spectroscopy. However, practice, clean robust MZMs have not been vortices due to contamination from...
The superconductivity of a kagome superconductor CsV_{3}Sb_{5} is studied by scanning tunneling microscopy and spectroscopy at ultralow temperature with high resolution. Two kinds superconducting gaps multiple sets coherent peaks residual zero-energy density states (DOS) are observed on both half-Cs Sb surfaces, implying multiband superconductivity. In addition, in-gap can be induced magnetic impurities but not nonmagnetic impurities, suggesting sign-preserving or s-wave order parameter....
We report that sizable single crystals of ${\mathrm{BaFe}}_{2}{\mathrm{As}}_{2}$ have been grown with the self-flux method. Measurements and anisotropy intrinsic transport magnetic properties from high-quality crystal are first presented. The resistivity (${\ensuremath{\rho}}_{c}/{\ensuremath{\rho}}_{ab}$) is as large 150 independent temperature. In contrast to susceptibility behavior observed in polycrystalline samples, no Curie-Weiss observed, a linear-$T$ dependent occurs...
Sr2IrO4 was predicted to be a high temperature superconductor upon electron doping since it highly resembles the cuprates in crystal structure, electronic structure and magnetic coupling constants. Here we report scanning tunneling microscopy/spectroscopy (STM/STS) study of with surface by depositing potassium (K) atoms. At 0.5-0.7 monolayer (ML) K coverage, observed sharp, V-shaped gap about 95% loss density state (DOS) at EFand visible coherence peaks. The magnitude is 25-30 meV for...
We synthesized the samples Sr(1-x)Sm(x)FFeAs with a ZrCuSiAs-type structure. These were characterized by resistivity and susceptibility. It is found that substitution of rare earth metal for alkaline in this system suppresses anomaly induces superconductivity. Superconductivity at 56 K nominal composition Sr(0.5)Sm(0.5)FFeAs realized, indicating superconducting transition temperatures iron arsenide fluorides can reach as high oxypnictides same
The correlation and competition between antiferromagnetism superconductivity are one of the most fundamental issues in high temperature superconductors. Superconductivity cuprate superconductors arises from suppressing an antiferromagnetic (AFM) Mott insulator1 while iron-pnictide AFM semimetals can coexist with orders2,3,4,5,6,7,8,9. This difference raises many intriguing debates on relation two classes Recently, at 32 K has been reported iron-chalcogenide AxFe2−ySe2 (A = K, Rb Cs)10,11,12....
We measure the resistivity and magnetic susceptibility in temperature range from 5 K to 600 for single crystals $A$Fe$_{2-y}$Se$_2$ ($A$ = K$_{0.8}$, Rb$_{0.8}$, Cs$_{0.8}$, Tl$_{0.5}$K$_{0.3}$ Tl$_{0.4}$Rb$_{0.4}$). A sharp superconducting transition is observed low susceptibility, shows 100% Meissner volume fraction all crystals, while an antiferromagnetic at Neel ($T_N$) as high 500 540 depending on A. It indicates coexistence of superconductivity antiferromagnetism. increase arises...
To understand the pairing symmetry and superconducting transition temperature in heavily electron-doped iron-based superconductors, it is important to study more of these materials, especially ones with decent stability air without phase separation. Here, angle-resolved photoemission spectroscopy probes surface electronic structure gap new superconductor (Li${}_{0.8}$Fe${}_{0.2}$)OHFeSe, which shows a ${T}_{c}$ as high 40 K.
Abstract Exotic quantum states arise from the interplay of various degrees freedom such as charge, spin, orbital, and lattice. Recently, a short-ranged charge order (CO) was discovered deep inside antiferromagnetic phase Kagome magnet FeGe, exhibiting close relationships with magnetism. Despite extensive investigations, CO mechanism remains controversial, mainly because behavior hinders precise identification superstructure. Here, combining multiple experimental techniques, we report...
We systematically investigated the in-plane resistivity anisotropy of electron-underdoped EuFe(2-x)Co(x)As(2) and BaFe(2-x)Co(x)As(2) hole-underdoped Ba(1-x)K(x)Fe(2)As(2). Large was found in former samples, while tiny detected latter ones. When it is detected, starts above structural transition temperature increases smoothly through it. As lowered further, takes a dramatic enhancement magnetic temperature. that universally tied to presence T-linear behavior resistivity. Our results...
We successfully grew the high-quality single crystals of ${A}_{x}$Fe${}_{2}$Se${}_{2}$ ($A$ $=$ K and Cs) by self-flux method. Sharp superconducting transition was observed for both types crystals. The show onset temperatures (${T}_{\mathrm{c}}$) 31 30 Cs compounds, respectively, with nearly 100$%$ superconductive shielding fraction. quite high resistivity in normal state more than 160 1300 $\mathrm{m}\ensuremath{\Omega}$ cm maximum ${\mathrm{K}}_{x}$Fe${}_{2}$Se${}_{2}$...
We measured the resistivity and magnetic susceptibility to map out phase diagram of single crystalline NaFe$_{1-x}$Co$_x$As. Replacement Fe by Co suppresses both structural transition, while enhances superconducting transition temperature ($T_{\rm c}$) component fraction. Magnetic exhibits temperature-linear dependence in high temperatures up 500 K for all samples, but such behavior suddenly breaks down non-superconducting overdoped crystal, suggesting that superconductivity is closely...
A new investigation of the candidate topological superconductor Cu${}_{x}$Bi${}_{2}$Se${}_{3}$ reveals microscopic details its superconductivity under various magnetic fields, which is potentially useful insight for quantum computing.
Kagome metals show rich competing quantum phases due to geometry frustration, flat bands, many-body effects, and nontrivial topology. Recently, a novel charge density wave (CDW) was discovered deep inside the antiferromagnetic phase of FeGe, attracting intense attention close relation with magnetism. Here, via scanning tunneling microscope (STM), we find 2 \ifmmode\times\else\texttimes\fi{} CDW in FeGe is very fragile can be readily disrupted into initial 1 phase; small \ensuremath{\surd}3...
We discover superconductivity in alkali-earth metals doped phenanthrene. The superconducting critical temperatures \emph{T}$_c$ are 5.6 K and 5.4 for Sr$_{1.5}$phenanthrene Ba$_{1.5}$phenanthrene, respectively. shielding fraction of Ba$_{1.5}$phenanthrene exceeds 65%. Raman spectra show 8 cm$^{-1}$/electron 7 downshifts the mode at 1441 cm$^{-1}$ due to charge transfer organic molecules from dopants Ba Sr. Similar behavior has been observed A$_3$phenanthrene A$_3$C$_{60}$(A = Rb). positive...
The compounds ${\text{Na}}_{2}{\text{Ti}}_{2}{P}_{2}\text{O}$ $(P=\text{As},\text{Sb})$ with anti-${\text{K}}_{2}{\text{NiF}}_{4}$ structure were characterized by magnetic susceptibility, magnetoresistance, Hall coefficient $({R}_{H})$, heat capacity, and thermoelectric power (TEP). These exhibit an anomalous transition in resistivity susceptibility at ${T}_{S}\ensuremath{\sim}320\text{ }\text{K}$ for ${\text{Na}}_{2}{\text{Ti}}_{2}{\text{As}}_{2}\text{O}$ ${T}_{S}\ensuremath{\sim}115\text{...
We studied the correlation among structure and transport properties superconductivity in different $A_x$Fe$_2$Se$_2$ single crystals ($A$ = K, Rb, Cs). Two sets of (00$l$) reflections are observed X-ray crystal diffraction patterns, arise from intrinsic inhomogeneous distribution intercalated alkali atoms. The occurrence is closely related to {\sl c}-axis lattice constant, $A$ content crucial superconductivity. hump resistivity seems be irrelevant There exist many deficiencies within FeSe...
Surface K–dosed (Li 0.8 Fe 0.2 OH)FeSe provides new clues to understand the mechanism of FeSe-based superconductors.
Two-dimensional materials represent a major frontier for research into exotic many-body quantum phenomena. In the extreme two-dimensional limit, electron-electron interaction often dominates over other electronic energy scales, leading to strongly correlated effects such as spin liquid and unconventional superconductivity. The dominance is conventionally attributed lack of electron screening in third dimension. Here, we discover an intriguing metal Mott insulator transition 1T-TaSe
The novel family of pnictide-oxides compounds (SrF)2Ti2Pn2O (Pn = As and Sb) (SmO) 2Ti2Sb2O were predicted from the stacking well-known fluorite type block [Sr2F2]2+ or [Sm2O2]2+ alternating regularly with anti-CuO2-type Ti2O square planar layer subsequently synthesized. samples (SmO)2Ti2Sb2O an anti-K2NiF4 characterized by X-ray diffraction, resistivity, susceptibility, Hall coefficient (RH), thermoelectric power (TEP), heat capacity. These exhibit anomalous transition in resistivity...