Novel surface states from antiferromagnetism

Surface states in NdBi
Surface states in NdBi. ARPES data at (a) T > TN and (b) T < TN. (c), (d)-(f), (g)-(i), and (j)-(k) show the structures and calculated surface states for non-magnetic (NM) and magnetic 1q, 2q, and 3q orders (multi-q), respectively.

Scientific Achievement

First-principles calculations reveal that unconventional surface states can arise from band-folding hybridization gap in a topological antiferromagnet.

Significance and Impact

Spin-textured surface states are a hallmark of topological insulators and Weyl semimetals. Our results point to a new mechanism to generate these states which broadens the pool of materials useful for future spintronics applications.

Research Details

  • Surface states are calculated for NdBi with multi-q AFM orders from density-functional theory and Wannier functions.
  • Multi-q structures host Dirac and Weyl nodes.
  • The calculated surface electron pockets and Fermi arc-like features with spin-texture agree with ARPES data but are found to originate from the band-folding hybridization gap formed from AFM order rather than from Weyl nodes.

L.-L. Wang, J. Ahn, R.-J. Slager, Y. Kushnirenko, B. G. Ueland, A. Sapkota, B. Schrunk, B. Kuthanazhi, R. J. McQueeney, P. C. Canfield, A. Kaminski, Commun Phys 6, 78 (2023).