Tunable surface plasmons in Weyl semimetals TaAs and NbAs

Comparative Raman study of Weyl semimetals TaAs, NbAs, TaP and NbP.

We report a comparative polarized Raman study of Weyl semimetals TaAs, NbAs, TaP and NbP. The evolution of the phonon frequencies with the sample composition allows us to determine experimentally which atoms are mainly involved for each vibration mode. Our results confirm previous first-principles calculations indicating that the A1, B1(2), E(2) and E(3) modes involve mainly the As(P) atoms, th...

Helicons in Weyl semimetals

Photocurrents in Weyl semimetals

Ching-Kit Chan,1 Netanel H. Lindner,2 Gil Refael,3 and Patrick A. Lee1 1Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA 2Physics Department, Technion, 320003 Haifa, Israel 3Institute of Quantum Information and Matter and Department of Physics, California Institute of Technology, Pasadena, California 91125, USA (Received 13 August 2016; revised m...

Towards three-dimensional Weyl-surface semimetals in graphene networks.

Graphene as a two-dimensional topological semimetal has attracted much attention for its outstanding properties. In contrast, three-dimensional (3D) topological semimetals of carbon are still rare. Searching for such materials with salient physics has become a new direction in carbon research. Here, using first-principles calculations and tight-binding modeling, we propose a new class of Weyl s...

Nonstoichiometry and Weyl fermionic behavior in TaAs

The band structure of TaAs provides the necessary conditions for the emergence of Weyl fermions. Measurements verifying this fact are remarkably robust, given the reported levels of nonstoichiometry in typical single crystals. Here we demonstrate the surprising fact that a small degree of nonstoichiometry is essential for such observations in a wide range of temperatures. From first principles,...