Spin Polarization And Texture Of The Fermi Arcs In The Weyl Fermion Semimetal Taas

Abstract

A Weyl semimetal is a new state of matter that hosts Weyl fermions as quasiparticle excitations. The Weyl fermions at zero energy correspond to points of bulk-band degeneracy, called Weyl nodes, which are separated in momentum space and are connected only through the crystal's boundary by an exotic Fermi arc surface state. We experimentally measure the spin polarization of the Fermi arcs in the first experimentally discovered Weyl semimetal TaAs. Our spin data, for the first time, reveal that the Fermi arcs' spin-polarization magnitude is as large as 80% and lies completely in the plane of the surface. Moreover, we demonstrate that the chirality of the Weyl nodes in TaAs cannot be inferred by the spin texture of the Fermi arcs. The observed nondegenerate property of the Fermi arcs is important for establishing its exact topological nature, which reveals that spins on the arc form a novel type of 2D matter. Additionally, the nearly full spin polarization we observed (∼80%) may be useful in spintronic applications.

Publication Date

3-1-2016

Publication Title

Physical Review Letters

Volume

116

Issue

9

Document Type

Article

Personal Identifier

scopus

DOI Link

https://doi.org/10.1103/PhysRevLett.116.096801

Socpus ID

84960517290 (Scopus)

Source API URL

https://api.elsevier.com/content/abstract/scopus_id/84960517290

This document is currently not available here.

Share

COinS