A5040274801- Topological Materials and Phenomena
- Electronic and Structural Properties of Oxides
- Magnetic properties of thin films
- Advanced Condensed Matter Physics
- Iron-based superconductors research
- Graphene research and applications
- Rare-earth and actinide compounds
- Physics of Superconductivity and Magnetism
- 2D Materials and Applications
- ZnO doping and properties
- Magnetic Properties and Applications
- Quantum, superfluid, helium dynamics
- Magnetic and transport properties of perovskites and related materials
- Heusler alloys: electronic and magnetic properties
- Inorganic Chemistry and Materials
- MXene and MAX Phase Materials
- Molecular Junctions and Nanostructures
- Organic and Molecular Conductors Research
- Theoretical and Computational Physics
- High-Energy Particle Collisions Research
- Advanced Memory and Neural Computing
- Characterization and Applications of Magnetic Nanoparticles
- Electric Motor Design and Analysis
- Advanced Thermoelectric Materials and Devices
- Ga2O3 and related materials
Tohoku University
1998-2025
Université Paris-Saclay
2025
Osaka University
2021
Nagoya University
1989-2005
Kagome metals $A{\mathrm{V}}_{3}{\mathrm{Sb}}_{5}$ ($A=\mathrm{K}$, Rb, and Cs) exhibit superconductivity at 0.9--2.5 K charge-density wave (CDW) 78--103 K. Key electronic states associated with the CDW remain elusive. Here, we investigate low-energy excitations of ${\mathrm{CsV}}_{3}{\mathrm{Sb}}_{5}$ by angle-resolved photoemission spectroscopy. We found an energy gap 50--70 meV Dirac-crossing points linearly dispersive bands, pointing to importance spin-orbit coupling. also a signature...
The KOTO collaboration has now carefully analyzed widely discussed preliminary data containing four signal events for a rare kaon decay---an excess suggesting physics beyond the Standard Model---and found that Model background are large enough to explain signal.
Dosing cesium atoms on the surface of CsV${}_{3}$Sb${}_{5}$ suppresses charge-density wave that typically coexists with its superconductivity, paving way to understanding interplay between these two phenomena.
Kagome lattices offer a fertile ground to explore exotic quantum phenomena associated with electron correlation and band topology. The recent discovery of superconductivity coexisting charge-density wave (CDW) in the kagome metals KV3Sb5, RbV3Sb5, CsV3Sb5 suggests an intriguing entanglement electronic order superconductivity. However, microscopic origin CDW, key understanding superconducting mechanism its possible topological nature, remains elusive. Here, we report angle-resolved...
Kagome metals AV_{3}Sb_{5} (A=K, Rb, and Cs) exhibit a characteristic superconducting ground state coexisting with charge density wave (CDW), whereas the mechanisms of superconductivity CDW have yet to be clarified. Here we report systematic angle-resolved photoemission spectroscopy (ARPES) study Cs(V_{1-x}Nb_{x})_{3}Sb_{5} as function Nb content x, where isovalent substitution causes an enhancement transition temperature (T_{c}) reduction (T_{CDW}). We found that shifts Sb-derived electron...
Polar surface and interface play pivotal roles for realizing exotic properties of materials, search such polar states is crucial importance expanding materials' functionality. Here we report microfocused angle-resolved photoemission spectroscopy ${\mathrm{CsV}}_{3}{\mathrm{Sb}}_{5}$, a member recently discovered kagome superconductors $A{\mathrm{V}}_{3}{\mathrm{Sb}}_{5}$ ($A$ = K, Rb, Cs) show evidence the nature cleaved which characterized by Cs- Sb-terminated surfaces with markedly...
Recently discovered kagome superconductors $A{\text{V}}_{3}{\text{Sb}}_{5}$ $(A=\mathrm{K}, \mathrm{Rb}, \mathrm{Cs})$ exhibit exotic bulk and surface physical properties such as charge density wave (CDW) chirality, whereas their origins remain unresolved. By using microfocused angle-resolved photoemission spectroscopy, we that commonly exhibits two distinct polar surfaces depending on the termination: electron- hole-doped ones for $A$ Sb termination, respectively. We observed kagome-derived...
Interplay between fermiology and electron correlation is crucial for realizing exotic quantum phases. Transition-metal dichalcogenide (TMD) 1T-TaS2 has sparked a tremendous attention owing to its unique Mott-insulating phase coexisting with the charge-density wave (CDW). However, how are associated such properties yet be claried. Here we demonstrate that monolayer 1T-NbTe2 new class of two-dimensional TMD which star-of-David lattice similarly bulk TaS2 isostructural NbSe2, but exhibits...
We have performed angle-resolved photoemission spectroscopy on epitaxial VTe2 films to elucidate the relationship between fermiology and charge-density waves (CDW). found that a two-dimensional triangular pocket in 1 monolayer (ML) is converted strongly warped quasi-one-dimensional (1D) Fermi surface 6ML counterpart, likely associated with 1T-to-1T' structural phase transition. also revealed metallic edge entire at low temperature distinct from anisotropic pseudogap 1ML, signifying contrast...
Abstract Applying lattice strain to thin films, a critical factor tailor their properties such as stabilizing structural phase unstable at ambient pressure, generally necessitates heteroepitaxial growth control the mismatch with substrate. Therefore, while homoepitaxy, of film on substrate made same material, is useful method fabricate high‐quality its application studying strain‐induced phases limited. Contrary this general belief, here quasi‐homoepitaxial Cs and Rb films reported...
Topological Dirac semimetals (TDSs) offer an excellent opportunity to realize outstanding physical properties distinct from those of topological insulators. Since TDSs verified so far have their own problems such as high reactivity in the atmosphere and difficulty controlling phases via chemical substitution, it is highly desirable find a new material platform TDSs. By angle-resolved photoemission spectroscopy combined with first-principles band-structure calculations, we show that ternary...
One of the key challenges in research topological insulators (TIs) is to establish a means intentionally manipulate Dirac fermions. While chemical substitution commonly applied control sign and filling carriers, it inevitably introduces disorders impurities into crystal, leading deterioration carrier properties. Here, we have experimentally established method free from such problems by fabricating TI/TI heterostructures. We grew n quintuple layers Bi2Te3 on Bi2Se3 visualized evolution band...