Presence of exotic electronic surface states in LaBi and LaSb

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

  • X. H. Niu - (Author)
  • D. F. Xu - (Author)
  • Y. H. Bai - (Author)
  • Q. Song - (Author)
  • X. P. Shen - (Author)
  • B. P. Xie - (Author)
  • D. C. Peets - , Fudan University (Author)
  • D. L. Feng - (Author)

Abstract

Extremely high magnetoresistance (XMR) in the lanthanum monopnictides LaX (X=Sb,Bi) has recently attracted interest in these compounds as candidate topological materials. However, their perfect electron-hole compensation provides an alternative explanation, so the possible role of topological surface states requires verification through direct observation. Our angle-resolved photoemission spectroscopy data reveal multiple Dirac-like surface states near the Fermi level in both materials. Intriguingly, we have observed circular dichroism in both surface and near-surface bulk bands. Thus the spin-orbit-coupling-induced orbital and spin angular momentum textures may provide a mechanism to forbid backscattering in zero field, suggesting that surface and near-surface bulk bands may contribute strongly to XMR in LaX. The extremely simple rocksalt structure of these materials and the ease with which high-quality crystals can be prepared suggest that they may be an ideal platform for further investigation of topological matter.

Details

Original languageEnglish
Article number165163
JournalPhysical review. B
Volume94
Publication statusPublished - 25 Oct 2016
Peer-reviewedYes
Externally publishedYes

External IDs

Scopus 84994235588

Keywords