A5101642867- Topological Materials and Phenomena
- Physics of Superconductivity and Magnetism
- Magnetic properties of thin films
- Graphene research and applications
- 2D Materials and Applications
- Advanced Condensed Matter Physics
- Quantum and electron transport phenomena
- Surface and Thin Film Phenomena
- Iron-based superconductors research
- Molecular Junctions and Nanostructures
- Perovskite Materials and Applications
- Electronic and Structural Properties of Oxides
- MXene and MAX Phase Materials
- Magnetic and transport properties of perovskites and related materials
- Advanced Chemical Physics Studies
- Surface Chemistry and Catalysis
- Cold Atom Physics and Bose-Einstein Condensates
- Porphyrin and Phthalocyanine Chemistry
- Superconductivity in MgB2 and Alloys
- Magnetic Properties of Alloys
- Magneto-Optical Properties and Applications
- Chalcogenide Semiconductor Thin Films
- Iron oxide chemistry and applications
- Biodiesel Production and Applications
- Hydrogen Storage and Materials
Fudan University
2015-2024
State Key Laboratory of Surface Physics
2017-2024
Baotou Central Hospital
2024
Weichai Power (China)
2023
Collaborative Innovation Center of Advanced Microstructures
2014-2022
ShangHai JiAi Genetics & IVF Institute
2022
Nanjing University
2022
Science and Technology on Surface Physics and Chemistry Laboratory
2020
Shanghai Jiao Tong University
2012-2017
Max Planck Society
2006-2015
Majorana fermion (MF) whose antiparticle is itself has been predicted in condensed matter systems. Signatures of the MFs have reported as zero energy modes various More definitive evidences are highly desired to verify existence MF. Very recently, theory induce spin selective Andreev reflection (SSAR), a novel magnetic property which can be used detect MFs. Here we report first observation SSAR from inside vortices Bi2Te3/NbSe2 hetero-structure, topological superconductivity was previously...
Three-dimensional topological insulators (TIs) are characterized by their nontrivial surface states, in which electrons have spin locked at a right angle to momentum under the protection of time-reversal symmetry. The topologically ordered phase TIs does not break any interplay between order and symmetry breaking, such as that observed superconductivity, can lead new quantum phenomena devices. We fabricated superconducting TI/superconductor heterostructure growing dibismuth triselenide...
By combining scanning tunneling microscopy and spectroscopy, angle-resolved photoemission density functional theory band calculations, we directly observe resolve the one-dimensional edge states of single bilayer (BL) Bi(111) islands on clean Bi(2)Te(3) Bi(111)-covered substrates. The are localized in vicinity step edges having an ∼2 nm wide spatial distribution real space reside energy gap BL. Our results demonstrate existence nontrivial topological as a two-dimensional insulator.
Controlling the crystal structure is a powerful approach for manipulating fundamental properties of solids. In van der Waals materials, this control can be achieved by modifying stacking order through rotation and translation between layers. Here, we observed stacking-dependent interlayer magnetism in two-dimensional (2D) magnetic semiconductor chromium tribromide (CrBr3), which was enabled successful growth its monolayer bilayer molecular beam epitaxy. Using situ spin-polarized scanning...
We report the observation of a dense triangular network one-dimensional (1D) metallic modes in continuous and uniform monolayer MoSe(2) grown by molecular-beam epitaxy. High-resolution transmission electron microscopy scanning tunneling spectroscopy studies show that these 1D are midgap states at inversion domain boundaries. Scanning measurements further reveal intensity undulations modes, presumably arising from superlattice potentials due to moiré pattern quantum confinement effect. A with...
Interest in two-dimensional (2D) transition-metal dichalcogenides (TMDs) has prompted some recent efforts to grow ultrathin layers of these materials epitaxially using molecular-beam epitaxy (MBE). However, growths monolayer (ML) and bilayer (BL) WSe2—an important member the TMD family—by MBE method remain uncharted, probably because difficulty generating tungsten fluxes from elemental source. In this work, we present a scanning tunneling microscopy spectroscopy (STM/S) study MBE-grown WSe2...
Silicene, a monolayer of silicon atoms arranged in honeycomb lattices, can be synthesized on the Ag(111) surface, where it forms several superstructures with different buckling patterns and periodicity. Using scanning tunneling microscopy (STM), we obtained high-resolution images silicene grown revealed its five phases, i.e., 4 × − α, β, β γ, some observed for first time. For each have determined atomic structure by comparing atomic-resolution STM theoretical simulation results previously...
The steady-state spectra and fluorescence lifetimes are investigated under vacuum for methylammonium lead bromide iodide (CH3NH3PbBr3 or MAPbBr3, CH3NH3PbI3 MAPbI3) thin films by stably controlling the sample temperature in range of 78 K to 320 K. transformation spectrum features lifetime components proved be quite sensitive temperatures accordance with phase transition structures. Our work demonstrates that halide anions I- Br- remarkable differences on optical characteristics. Due distinct...
Bilayer (BL) MoSe2 films grown by molecular-beam epitaxy (MBE) are studied scanning tunneling microscopy and spectroscopy (STM/S). Similar to monolayer (ML) films, networks of inversion domain boundary (DB) defects observed both in the top bottom layers BL MoSe2, often they seen spatially correlated such that one is on other. There also isolated ones layer without companion top-layer detected STM/S through quantum defect states barrier ML. Comparing DB with ML film reveals some common...
Ultrathin freestanding bismuth film is theoretically predicted to be one kind of two-dimensional topological insulators. Experimentally, the nature strongly depends on situations Bi films. Film thickness and interaction with substrate often change properties Using angle-resolved photoemission spectroscopy, scanning tunneling microscopy or spectroscopy first-principle calculation, Bi(111) ultrathin grown NbSe2 superconducting have been studied. We find band structures quasi-freestanding,...
Monolayer (ML) transition metal dichalcogenides (TMDs) have been attracting great research attentions lately for their extraordinary properties, in particular the exotic spin-valley coupled electronic structures that promise future spintronic and valleytronic applications1-3. The energy bands of ML TMDs well separated valleys constitute effectively an extra internal degree freedom low carriers3-12. large spin-orbit coupling makes spin index locked to valley index, which has some interesting...
We have achieved the growth of monolayer FeCl<sub>2</sub> on HOPG substrate by molecular beam epitaxy. The thin film is found to be insulating associated with momentum filtered tunneling effects using scanning microscope.
With spin-polarized scanning tunneling microscopy operating in the constant current mode, 120 degrees antiferromagnetic Néel structure was found for a monolayer Mn on Ag(111) both fcc and hcp stacking. The existence of structurally equivalent, but magnetically distinguished, islands observed. While display frustrated spin structure, orientations their magnetic moments differ by 30 possibly due to spin-orbit coupling.
By combining angle-resolved photoemission spectroscopy and first-principles calculations, we systematically studied the electronic structures of ultrathin Bi(111) films ($\ensuremath{\le}5$ bilayers) epitaxially grown on ${\mathrm{Bi}}_{2}{\mathrm{Te}}_{3}$. High-resolution low-energy band dispersions Fermi surfaces $\mathrm{Bi}(111)/{\mathrm{Bi}}_{2}{\mathrm{Te}}_{3}$ as a function thickness were experimentally determined. Our results also indicate that epitaxial Bi are strongly influenced...
Using high-resolution angle-resolved photoemission spectroscopy and scanning tunneling microscopy/spectroscopy, the atomic low energy electronic structure of Sr-doped superconducting topological insulators (SrxBi2Se3) was studied. Scanning microscopy shows that most Sr atoms are not in van der Waals gap. After doping, Fermi level found to move further upwards when compared with parent compound Bi2Se3, which is consistent carrier density this system. The surface state clearly observed,...
Using spin-polarized scanning tunneling microscopy with ring electrodes, the in-plane spin polarization of Mn on Fe(001) was measured. A large $(\sqrt{1}0\ifmmode\times\else\texttimes\fi{}2\sqrt{1}0)R18.4\ifmmode^\circ\else\textdegree\fi{}$ reconstruction a noncollinear structure found. By combining maps for two orthogonal directions, vector field in unit cell could be constructed. The complex behavior is explained basis tendency to form antiferromagnetically coupled surface dimers.
Hot electrons injected into antiferromagnetic Mn layers from the tip of a low temperature scanning tunneling microscope have been used to determine energies, lifetimes, and momenta spin waves on nanometer scale. The show linear dispersion with velocity 160+/-10 meV A lifetimes that scale linearly energy in agreement neutron scattering theory. It is shown method sensitive enough detect influence surface anisotropies wave dispersion.