Yun Wu

Discovery of a Weyl fermion state with Fermi arcs in niobium arsenide

We report the discovery of Weyl semimetal NbAs featuring topological Fermi arc surface states.

Spectroscopic evidence for a type II Weyl semimetallic state in MoTe2

In a type I Dirac or Weyl semimetal, the low-energy states are squeezed to a single point in momentum space when the chemical potential μ is tuned precisely to the Dirac/Weyl point. Recently, a type II Weyl semimetal was predicted to exist, where the Weyl states connect hole and electron bands, separated by an indirect gap. This leads to unusual energy states, where hole and electron pockets touch at the Weyl point. Here we present the discovery of a type II topological Weyl semimetal state in pure MoTe2, where two sets of Weyl points (, ) exist at the touching points of electron and hole pockets and are located at different binding energies above EF. Using angle-resolved photoemission spectroscopy, modelling, density functional theory and calculations of Berry curvature, we identify the Weyl points and demonstrate that they are connected by different sets of Fermi arcs for each of the two surface terminations. We also find new surface track states that form closed loops and are unique to type II Weyl semimetals. This material provides an exciting, new platform to study the properties of Weyl fermions.

Observation of Fermi arcs in the type-II Weyl semimetal candidate WTe2

In recently predicted type-II Weyl semimetals, the Weyl states connect hole and electron bands that would otherwise be separated by an indirect gap. The set of points in the momentum space at which both bands touch are called Weyl points and are connected by Fermi arcs at the surface of the sample. Experimental evidence confirmed existence of these exotic fermions in MoTe

Anomalous temperature-dependent transport in YbNi2B2C and its correlation to microstructural features

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Dirac node arcs in PtSn4

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Fermi arc electronic structure and Chern numbers in the type-II Weyl semimetal candidateMoxW1−xTe2

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Temperature-Induced Lifshitz Transition in WTe2.

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Enhancement of the Superconducting Gap by Nesting in CaKFe4As4: A New High Temperature Superconductor

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Asymmetric mass acquisition in LaBi. Topological semimetal candidate

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Electronic structure of RSb ( R=Y, Ce, Gd, Dy, Ho, Tm, Lu) studied by angle-resolved photoemission spectroscopy

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