A5075909473- Physics of Superconductivity and Magnetism
- Semiconductor materials and devices
- Advanced Condensed Matter Physics
- Advancements in Semiconductor Devices and Circuit Design
- Iron-based superconductors research
- Magnetic and transport properties of perovskites and related materials
- Quantum chaos and dynamical systems
- Rare-earth and actinide compounds
- Superconductivity in MgB2 and Alloys
- Integrated Circuits and Semiconductor Failure Analysis
- Advanced Chemical Physics Studies
- Electronic and Structural Properties of Oxides
- Nonlinear Photonic Systems
- Advanced Differential Equations and Dynamical Systems
- Nonlinear Dynamics and Pattern Formation
- High-pressure geophysics and materials
- Inorganic Fluorides and Related Compounds
- Superconducting Materials and Applications
- Semiconductor materials and interfaces
- Ferroelectric and Negative Capacitance Devices
- Radiation Effects in Electronics
- Magnetic properties of thin films
- Radio Frequency Integrated Circuit Design
- Corporate Taxation and Avoidance
- Silicon Nanostructures and Photoluminescence
Institute of Physics
2013-2023
University of Chinese Academy of Sciences
2017-2023
Songshan Lake Materials Laboratory
2021-2023
Hunan Normal University
2012-2023
Chinese Academy of Sciences
2013-2021
National Laboratory for Superconductivity
2014-2021
Beijing Academy of Quantum Information Sciences
2021
Collaborative Innovation Center of Quantum Matter
2017-2018
Tongji University
2012
Vanderbilt University
2003-2010
The topological materials have attracted much attention for their unique electronic structure and peculiar physical properties. ZrTe5 has host a long-standing puzzle on its anomalous transport properties manifested by unusual resistivity peak the reversal of charge carrier type. It is also predicted that single-layer two-dimensional insulator there possibly phase transition in bulk ZrTe5. Here we report high-resolution laser-based angle-resolved photoemission measurements detailed...
Quasiparticle dispersion in Bi2Sr2CaCu2O8 is investigated with improved angular resolution as a function of temperature and doping. Unlike the linear predicted by band calculation, data show sharp break at 50+/-15 meV binding energy where velocity changes factor 2 or more. This change provides an scale quasiparticle self-energy. evident away from d-wave node line, but magnitude decreases increasing
We have performed a systematic doping dependent study of La$_{2-x}$Sr$_x$CuO$_4$ (LSCO) (0.03$\leq x \leq$0.3) by angle-resolved photoemission spectroscopy. In the entire range, underlying ``Fermi surface" determined from low energy spectral weight approximately satisfies Luttinger's theorem, even down to lightly-doped region. This is in strong contrast result on Ca$_{2-x}$Na$_x$CuO$_2$Cl$_2$ (Na-CCOC), which shows deviation theorem. The differences between LSCO and Na-CCOC are correlated...
Angle-resolved photoemission spectroscopy (ARPES) on optimally doped Bi2Sr2Ca0.92Y0.08Cu2O(8+delta) uncovers a coupling of the electronic bands to 40 meV mode in an extended k-space region away from nodal direction, leading new interpretation strong renormalization structure seen Bi2212. Phenomenological agreements with neutron and Raman experiments suggest that this is B1g oxygen bond-buckling phonon. A theoretical calculation based assignment reproduces data.
We report first-principles calculations that elucidate the mechanisms underlie key features of negative-bias temperature instability (NBTI). show depassivation Si–H bonds by protons released in Si substrate is consistent with observed increase interface-trap density. The calculated activation energy 0.36eV excellent agreement observations for long stress times. Adequate amounts hydrogen, needed to initiate depassivation, are likely exist substrate, trapped complexes dopants. role holes H...
The iron-based superconductors are characterized by multiple-orbital physics where all the five Fe 3$d$ orbitals get involved. nature gives rise to various novel phenomena like orbital-selective Mott transition, nematicity and orbital fluctuation that provide a new route for realizing superconductivity. complexity of also asks disentangle relationship between orbital, spin nematicity, identify dominant ingredients dictate bulk FeSe superconductor provides an ideal platform address these...
The latest discovery of high temperature superconductivity near 80K in La3Ni2O7 under pressure has attracted much attention. Many proposals are put forth to understand the origin superconductivity.The determination electronic structures is a prerequisite establish theories nickelates but still lacking. Here we report our direct measurement by high-resolution angle resolved photoemission spectroscopy. Fermi surface and band observed compared with structure calculations. Strong electron...
High resolution angle-resolved photoemission measurements on an underdoped $({\mathrm{La}}_{2\ensuremath{-}x}{\mathrm{Sr}}_{x}){\mathrm{CuO}}_{4}$ system show that, at energies below 70 meV, the quasiparticle peak is well defined around $(\ensuremath{\pi}/2,\ensuremath{\pi}/2)$ nodal region and disappears rather abruptly when momentum changed from point to $(\ensuremath{\pi},0)$ antinodal along underlying ``Fermi surface.'' It indicates that there extra low energy scattering mechanism acting...
The low-energy electronic structure of the nearly optimally doped trilayer cuprate superconductor Bi(2)Sr(2)Ca(2)Cu(3)O(10+delta) is investigated by angle-resolved photoemission spectroscopy. normal state quasiparticle dispersion and Fermi surface superconducting d-wave gap coherence peak are observed compared with those single- bilayer systems. We find that both magnitude relative coherence-peak intensity scale linearly T(c) for various materials.
We propose a systematic procedure to directly extract the Eliashberg function for electron-phonon coupling from high-resolution angle-resolved photoemission measurement. The is successfully applied Be(10(-)10) surface, providing new insights into at this surface. method shown be robust against imperfections in experimental data and suitable wider applications.
Angle-resolved photoemission spectroscopy data for the bilayer manganite La1.2Sr1.8Mn2O7 show that, upon lowering temperature below Curie point, a coherent polaronic metallic groundstate emerges very rapidly with well defined quasiparticles which track remarkably electrical conductivity, consistent macroscopic transport properties. Our suggest that mechanism leading to insulator-to-metal transition in can be regarded as polaron coherence condensation process acting concert Double Exchange...
Abstract Angle-resolved photoemission spectroscopy (ARPES) has become a cornerstone technique for elucidating the electronic structures of emergent quantum materials. Among these, kagome materials—distinguished by their two-dimensional lattice corner-sharing triangles—provide fertile ground investigating exotic phenomena, driven geometric frustration, correlation, and topology. In this review, we present overview recent ARPES studies on transition-metal We first outline fundamental features...
Heavy-fermion compounds ${\mathrm{YbIr}}_{2}{\mathrm{Si}}_{2}$ and ${\mathrm{YbRh}}_{2}{\mathrm{Si}}_{2}$ were studied by means of angle-resolved photoemission (PE). The splittings dispersions the $4{f}^{13}$ bulk surface PE signals in region expected energy crossings $4f$ final states valence bands Brillouin zone are observed. experimental results explained terms a simplified periodic Anderson model momentum dependence electron hopping matrix element between valence-band states.
Spin excitations in the overdoped high temperature superconductors Tl$_2$Ba$_2$CuO$_{6+\delta}$ and (Bi,Pb)$_2$(Sr,La)$_{2}$CuO$_{6+\delta}$ were investigated by resonant inelastic x-ray scattering (RIXS) as functions of doping detuning incoming photon energy above Cu-$L_3$ absorption peak. The RIXS spectra at optimal are dominated a paramagnon feature with peak independent energy, similar to prior results on underdoped cuprates. Beyond doping, data indicate sharp crossover regime strong...
The low-energy excitations of the lightly doped cuprates were studied by angle-resolved photoemission spectroscopy. A finite gap was measured over entire Brillouin zone, including along ${d}_{{x}^{2}\ensuremath{-}{y}^{2}}$ nodal line. This effect observed to be generic normal states numerous cuprates, hole-doped ${\mathrm{La}}_{2\ensuremath{-}x}{\mathrm{Sr}}_{x}{\mathrm{CuO}}_{4}$ and ${\mathrm{Ca}}_{2\ensuremath{-}x}{\mathrm{Na}}_{x}{\mathrm{CuO}}_{2}{\mathrm{Cl}}_{2}$ electron-doped...
Charge trapping characteristics are investigated for MOS capacitors with 6.8 nm HfO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> layers and 1.0 interfacial silicon oxynitrides; the effective oxide thickness of high-kappa gate dielectric is 2.1 nm. These devices were irradiated 10-keV X-rays or subjected to constant voltage stress, then annealed ten minute intervals alternating positive negative bias at temperatures between 25 150degC....
Hydrogen plays a central role in several reliability-related phenomena electronic devices. Here, we review an extensive set of first-principles calculations on H effects Si-based The results provide framework for the explanation physical processes responsible bias-temperature instability (BTI). We also examine new dissociation reaction Si-H bond at interface. find that process has barriers more than 2.3 eV; this precludes from being creation interface traps moderate temperatures involved...
Angle-resolved photoemission spectra of the heavy-fermion system YbIr(2)Si(2) are reported that reveal strong momentum (k) dependent splittings 4f(13) bulk and surface emissions around expected intersection points 4f final states with valence bands in Brillouin zone. The obtained dispersion is explained terms a simplified periodic Anderson model by k dependence electron hopping matrix element disregarding clearly interpretation single-impurity model.
We propose that a defect complex comprising suboxide Hf–Si bond and an interfacial dangling is responsible for the stress-induced buildup of interface traps in Si∕SiO2∕HfO2 capacitors. With aid first-principles calculations, we show these defects possess symmetric double-well energy minimum with moderate intervening barrier. The calculated activation energies suggest relatively easy hopping H atoms between two minima (a field-aided shuttling mechanism). This mechanism can explain...
Fluorine is known to have both a beneficial and adverse role on the characteristics of Si–SiO2-based devices. Here we report results first-principles calculations in terms which elucidate this dual behavior. On one hand, find that Si–F interfacial bonds are resistant depassivation by hydrogen species, with process being shut down presence holes. However, also show any excess fluorine has negative effect since it either creates stretched bonds, can act as carrier traps, or disrupts an abrupt...