Gap-like feature observed in the non-magnetic topological insulators.

Non-magnetic gap at the Dirac point of topological insulators remains an open question in the field. Here, we present angle-resolved photoemission spectroscopy experiments performed on Cr-doped BiSe and showed that the Dirac point is progressively buried by the bulk bands and a low spectral weight region in the vicinity of the Dirac point appears. These two mechanisms lead to spectral weight suppression region being mistakenly identified as an energy gap in earlier studies.

Realization of a Type-II Nodal-Line Semimetal in MgBi.

Nodal-line semimetals (NLSs) represent a new type of topological semimetallic phase beyond Weyl and Dirac semimetals in the sense that they host closed loops or open curves of band degeneracies in the Brillouin zone. Parallel to the classification of type-I and type-II Weyl semimetals, there are two types of NLSs. The type-I NLS phase has been proposed and realized in many compounds, whereas the exotic type-II NLS phase that strongly violates Lorentz symmetry has remained elusive.

Correction: Origin of the temperature dependence of the energy gap in Cr-doped BiSe.

Correction for 'Origin of the temperature dependence of the energy gap in Cr-doped Bi2Se3' by Turgut Yilmaz et al., Phys. Chem.

Origin of the temperature dependence of the energy gap in Cr-doped BiSe.

Recent progress in impurity-doped topological insulators has shown that the gap at the Dirac point shrinks with reducing temperature. This is an obstacle for experimental realization of the quantum anomalous Hall effect at higher temperature due to the requirement of a larger energy gap. In order to solve this puzzle, we study the gap at the Dirac point by performing temperature-dependent photoemission spectroscopy and X-ray diffraction experiments in Cr-doped Bi2Se3.

Structural phase diagram for ultra-thin epitaxial Fe3O4 / MgO(0 0 1) films: thickness and oxygen pressure dependence.

A systematic investigation of the thickness and oxygen pressure dependence for the structural properties of ultra-thin epitaxial magnetite (Fe3O4) films has been carried out; for such films, the structural properties generally differ from those for the bulk when the thickness  ⩽10 nm. Iron oxide ultra-thin films with thicknesses varying from 3 nm to 20 nm were grown on MgO (0 0 1) substrates using molecular beam epitaxy under different oxygen pressures ranging from 1  ×  10(-7) torr to 1  ×  10(-5) torr. The crystallographic and electronic structures of the films were characterized using low energy electron diffraction (LEED) and x-ray photoemission spectroscopy (XPS), respectively.