skip to main content


This content will become publicly available on May 18, 2019

Title: Nontrivial Nature and Penetration Depth of Topological Surface States in SmB 6 Thin Films

The nontrivial feature and penetration depth of the topological surface states (TSS) in SmB 6 were studied via spin pumping. The experiments used SmB 6 thin films grown on the bulk magnetic insulator Y 3Fe 5O 12 (YIG). Upon the excitation of magnetization precession in the YIG, a spin current is generated in the SmB 6 that produces, via spin--orbit coupling, a lateral electrical voltage in the film. This spin-pumping voltage signal becomes considerably stronger as the temperature decreases from 150 to 10 K, and such an enhancement most likely originates from the spin-momentum locking of the TSS and may thereby serve as evidence for the nontrivial nature of the TSS. The voltage data also show a unique film thickness dependence that suggests a TSS depth of ~32 nm. Finally, the spin--pumping results arc supported by transport measurements and analyses using a tight binding model.
 [1] ;  [2] ;  [3] ;  [4] ;  [1] ;  [1] ;  [5] ;  [4] ;  [4] ;  [3] ;  [2] ;  [1]
  1. Colorado State Univ., Fort Collins, CO (United States)
  2. Johns Hopkins Univ., Baltimore, MD (United States)
  3. Univ. of California, Irvine, CA (United States)
  4. Argonne National Lab. (ANL), Lemont, IL (United States)
  5. Colorado State Univ., Fort Collins, CO (United States); St. Petersburg Electrotechnical Univ., St. Petersburg (Russia)
Publication Date:
Grant/Contract Number:
AC02-06CH11357; SC0009390; SC0012670
Accepted Manuscript
Journal Name:
Physical Review Letters
Additional Journal Information:
Journal Volume: 120; Journal Issue: 20; Journal ID: ISSN 0031-9007
American Physical Society (APS)
Research Org:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Country of Publication:
United States
OSTI Identifier:
Alternate Identifier(s):
OSTI ID: 1437688