Orbital-selective effect of spin reorientation on the Dirac fermions in a non-charge-ordered kagome ferromagnet FeGe.

Kagome magnets provide a fascinating platform for the realization of correlated topological quantum phases under various magnetic ground states. However, the effect of the magnetic spin configurations on the characteristic electronic structure of the kagome-lattice layer remains elusive. Here, utilizing angle-resolved photoemission spectroscopy and density functional theory calculations, we report the spectroscopic evidence for the spin-reorientation effect of a kagome ferromagnet FeGe, which is composed solely of kagome planes.

Dirac cone, flat band and saddle point in kagome magnet YMnSn.

Kagome-lattices of 3d-transition metals hosting Weyl/Dirac fermions and topological flat bands exhibit non-trivial topological characters and novel quantum phases, such as the anomalous Hall effect and fractional quantum Hall effect. With consideration of spin-orbit coupling and electron correlation, several instabilities could be induced. The typical characters of the electronic structure of a kagome lattice, i.

Orbital-selective Dirac fermions and extremely flat bands in frustrated kagome-lattice metal CoSn.

Layered kagome-lattice 3d transition metals are emerging as an exciting platform to explore the frustrated lattice geometry and quantum topology. However, the typical kagome electronic bands, characterized by sets of the Dirac-like band capped by a phase-destructive flat band, have not been clearly observed, and their orbital physics are even less well investigated. Here, we present close-to-textbook kagome bands with orbital differentiation physics in CoSn, which can be well described by a minimal tight-binding model with single-orbital hopping in Co kagome lattice.

Intrinsic magnetic topological insulator phases in the Sb doped MnBiTe bulks and thin flakes.

Magnetic topological insulators (MTIs) offer a combination of topologically nontrivial characteristics and magnetic order and show promise in terms of potentially interesting physical phenomena such as the quantum anomalous Hall (QAH) effect and topological axion insulating states. However, the understanding of their properties and potential applications have been limited due to a lack of suitable candidates for MTIs. Here, we grow two-dimensional single crystals of Mn(SbBi)Te bulk and exfoliate them into thin flakes in order to search for intrinsic MTIs.

Author Correction: Large intrinsic anomalous Hall effect in half-metallic ferromagnet CoSnS with magnetic Weyl fermions.

The original version of this Article incorrectly omitted an affiliation of Hongming Weng: "Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, 100190, Beijing, China"This has been corrected in both the PDF and HTML versions of the Article.

Large intrinsic anomalous Hall effect in half-metallic ferromagnet CoSnS with magnetic Weyl fermions.

The origin of anomalous Hall effect (AHE) in magnetic materials is one of the most intriguing aspects in condensed matter physics and has been a controversial topic for a long time. Recent studies indicate that the intrinsic AHE is closely related to the Berry curvature of occupied electronic states. In a magnetic Weyl semimetal with broken time-reversal symmetry, there are significant contributions to Berry curvature around Weyl nodes, possibly leading to a large intrinsic AHE.

FeTeSe monolayer films: towards the realization of high-temperature connate topological superconductivity.

We performed angle-resolved photoemission spectroscopy studies on a series of FeTeSe monolayer films grown on SrTiO. The superconductivity of the films is robust and rather insensitive to the variations of the band position and effective mass caused by the substitution of Se by Te. However, the band gap between the electron- and hole-like bands at the Brillouin zone center decreases towards band inversion and parity exchange, which drive the system to a nontrivial topological state predicted by theoretical calculations.

Corrugation in exfoliated graphene: an electron microscopy and diffraction study.

Low-energy electron microscopy and microprobe diffraction are used to image and characterize corrugation in SiO(2)-supported and suspended exfoliated graphene at nanometer length scales. Diffraction line-shape analysis reveals quantitative differences in surface roughness on length scales below 20 nm which depend on film thickness and interaction with the substrate. Corrugation decreases with increasing film thickness, reflecting the increased stiffness of multilayer films.

Quantized electron accumulation states in indium nitride studied by angle-resolved photoemission spectroscopy.

Electron accumulation states in InN have been measured using high resolution angle-resolved photoemission spectroscopy (ARPES). The electrons in the accumulation layer have been discovered to reside in quantum well states. ARPES was also used to measure the Fermi surface of these quantum well states, as well as their constant binding energy contours below the Fermi level E(F).