A5074937761- Physics of Superconductivity and Magnetism
- Advanced Condensed Matter Physics
- Iron-based superconductors research
- Magnetic and transport properties of perovskites and related materials
- Rare-earth and actinide compounds
- Corporate Taxation and Avoidance
- Copper-based nanomaterials and applications
- Electronic and Structural Properties of Oxides
- Quantum many-body systems
- Topological Materials and Phenomena
- Superconducting Materials and Applications
- Magnetic confinement fusion research
Institute of Physics
2020-2024
National Laboratory for Superconductivity
2020-2024
Chinese Academy of Sciences
2020-2024
University of Chinese Academy of Sciences
2020-2023
Single-layer FeSe films grown on the SrTiO3 substrate (FeSe/STO) have attracted much attention because of their possible record-high superconducting critical temperature Tc and distinct electronic structures in iron-based superconductors. However, it has been under debate how high its can really reach due to inconsistency results obtained from transport, magnetic spectroscopic measurements. Here we report evidence superconductivity pairing at 83 K single-layer FeSe/STO films. By preparing...
As the number of CuO2 layers, n, in each unit cell a cuprate family increases, maximum transition temperature (Tc,max) exhibits universal bell-shaped curve with peak at n = 3. The microscopic mechanism this trend remains elusive. In study, we used advanced electron microscopy to image atomic structure cuprates Bi2Sr2Can-1CunO2n+4+δ 1 ≤ 9; evolution charge-transfer gap size (Δ) can be measured simultaneously. We determined that dependence Δ follows an inverted minimum value correlation...
We report high-resolution laser-based angle-resolved photoemission spectroscopy measurements on a newly discovered iron-based superconductor, KCa2Fe4As4F2 (TC=33.5 K), which consists of stacking FeAs blocks with two layers separated by insulating Ca2F2 blocks. Bilayer splitting effect is observed for the first time in superconductors that gives rise to total five holelike Fermi surface sheets around Brillouin zone center. Band structure calculations reproduce bilayer identifying interlayer...
The microscopic mechanism for the disappearance of superconductivity in overdoped cuprates is still under heated debate. Here we use scanning tunneling spectroscopy to investigate evolution quasiparticle interference phenomenon Bi2Sr2CuO6+δ over a wide range hole densities. We find that when system enters regime, peculiar wavevector with arc-like pattern starts emerge even at zero bias, and its intensity grows increasing doping level. Its energy dispersion incompatible octet model d-wave...
Experiments reveal that the iron-based superconductor FeSe has a richer electronic structure than previously known, which may further studies into its rich physical properties and superconductivity mechanism.
In conventional superconductors, electron-phonon coupling plays a dominant role in generating superconductivity. high-temperature cuprate the existence of electron with phonons and other boson modes its producing superconductivity remain unclear. The evidence electron-boson mainly comes from angle-resolved photoemission (ARPES) observations <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"> <mml:mo>∼</mml:mo> </mml:math> 70-meV nodal dispersion kink...
Magnetic topological materials have attracted much attention due to the correlation between topology and magnetism. Recent studies suggest that EuCd$_2$As$_2$ is an antiferromagnetic material. Here by carrying out thorough magnetic, electrical thermodynamic property measurements, we discover a long time relaxation of magnetic susceptibility in EuCd$_2$As$_2$. The (001) in-plane at 5 K found continuously increase up $\sim$10% over $\sim$14 hours. anisotropic strongly depends on temperature...
The newly discovered Kagome superconductors AV$_3$Sb$_5$ (A=K, Rb and Cs) continue to bring surprises in generating unusual phenomena physical properties, including anomalous Hall effect, unconventional charge density wave, electronic nematicity time-reversal symmetry breaking. Here we report an unexpected emergence of multiple flat bands the superconductors. By performing high-resolution angle-resolved photoemission (ARPES) measurements, observed four branches that span over entire momentum...
The pseudogap state is one of the most enigmatic characteristics in anomalous normal properties high temperature cuprate superconductors. A central issue to reveal whether there a symmetry breaking and which symmetries are broken across transition. By performing resolution laser-based angle-resolved photoemission measurements on optimally-doped Bi 2 Sr 1.6 La 0.4 CuO 6+ δ superconductor, we report observations particle–hole conservation both superconducting along entire Fermi surface. These...
High temperature superconductivity in cuprates is realized by doping the Mott insulator with charge carriers. A central issue how such an insulating state can evolve into a conducting or superconducting when carriers are introduced. Here, situ vacuum annealing and Rb deposition on Bi2Sr2Ca0.6Dy0.4Cu2O8+delta (Bi2212) sample surface to push its level continuously from deeply underdoped (Tc=25 K, p-0.066) near zero parent insulator, angle-resolved photoemission spectroscopy measurements...
The spatially-resolved laser-based high resolution ARPES measurements have been performed on the optimally-doped $\mathrm{YBa_{2} Cu_{3} O_{7-\delta} }$ (Y123) superconductor. For first time, we found region from cleaved surface that reveals clear bulk electronic properties. intrinsic Fermi and band structures of Y123 are observed. surface-dependent momentum-dependent superconducting gap is determined which nodeless consistent with d+is form.