Ultrafast high-endurance memory based on sliding ferroelectrics

Science · 2024 · 154 citations

• Materials science
• Physical medicine and rehabilitation
• Medicine

switching cycles, comparable to state-of-the-art FeFET devices. These characteristics highlight the potential of 2D sliding ferroelectrics for inspiring next-generation nonvolatile memory technology.

Twofold van Hove singularity and origin of charge order in topological kagome superconductor CsV3Sb5

Nature Physics · 2022 · 399 citations

• Physics
• Condensed matter physics
• Quantum mechanics

Charge order landscape and competition with superconductivity in kagome metals

Nature Materials · 2022 · 98 citations

• Condensed matter physics
• Materials science
• Physics

Evidence of two-dimensional flat band at the surface of antiferromagnetic kagome metal FeSn

Nature Communications · 2021 · 71 citations

• Condensed matter physics
• Materials science
• Optoelectronics

, we observe an anomalous enhancement in tunneling conductance within a finite energy range of FeSn. Our first-principles calculations show this is consistent with a spin-polarized flat band localized at the ferromagnetic kagome layer at the Schottky interface. The spectroscopic capability to characterize the electronic structure of a kagome compound at a thin film heterointerface will provide a unique opportunity to probe flat band induced phenomena in an energy-resolved fashion with simultaneous electrical tuning of its properties. Furthermore, the exotic surface state discussed herein is expected to manifest as peculiar spin-orbit torque signals in heterostructure-based spintronic devices.

Topological flat bands in frustrated kagome lattice CoSn.

Nature Communications · 2020 · 365 citations

• Physics
• Condensed matter physics
• Quantum mechanics

Electronic flat bands in momentum space, arising from strong localization of electrons in real space, are an ideal stage to realize strongly-correlated phenomena. Theoretically, the flat bands can naturally arise in certain geometrically frustrated lattices, often with nontrivial topology if combined with spin-orbit coupling. Here, we report the observation of topological flat bands in frustrated kagome metal CoSn, using angle-resolved photoemission spectroscopy and band structure calculations. Throughout the entire Brillouin zone, the bandwidth of the flat band is suppressed by an order of magnitude compared to the Dirac bands originating from the same orbitals. The frustration-driven nature of the flat band is directly confirmed by the chiral d-orbital texture of the corresponding real-space Wannier functions. Spin-orbit coupling opens a large gap of 80 meV at the quadratic touching point between the Dirac and flat bands, endowing a nonzero Z2 invariant to the flat band. These findings demonstrate that kagome-derived flat bands are a promising platform for novel emergent phases of matter at the confluence of strong correlation and topology.

Enhancement of van der Waals Interlayer Coupling through Polar Janus MoSSe

Journal of the American Chemical Society · 2020 · 162 citations

• Chemistry
• Condensed matter physics
• Chemical physics

counterparts. Our noncontact ultralow-frequency Raman probe, linear chain model, and density functional theory calculations confirm the enhancement and reveal the origins as charge redistribution in Janus MoSSe and reduced interlayer distance. Our results uncover the potential of tuning interlayer coupling strength through Janus heterostacking.