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This content will become publicly available on November 1, 2018

Title: Dirac-electron-mediated magnetic proximity effect in topological insulator/magnetic insulator heterostructures

The possible realization of dissipationless chiral edge current in a topological insulator/magnetic insulator heterostructure is based on the condition that the magnetic proximity exchange coupling at the interface is dominated by the Dirac surface states of the topological insulator. We report a polarized neutron reflectometry observation of Dirac-electron-mediated magnetic proximity effect in a bulk-insulating topological insulator (Bi 0.2Sb 0.8) 2Te 3/magnetic insulator EuS heterostructure. We are able to maximize the proximity-induced magnetism by applying an electrical back gate to tune the Fermi level of topological insulator to be close to the Dirac point. A phenomenological model based on diamagnetic screening is developed to explain the suppressed proximity-induced magnetism at high carrier density. Our work paves the way to utilize the magnetic proximity effect at the topological insulator/magnetic insulator heterointerface for low-power spintronic applications.
Authors:
 [1] ;  [1] ;  [2] ;  [3] ;  [1] ;  [3] ;  [3] ;  [1] ;  [2] ;  [1] ;  [4]
  1. Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)
  2. Pennsylvania State Univ., University Park, PA (United States)
  3. Brookhaven National Lab. (BNL), Upton, NY (United States)
  4. Pennsylvania State Univ., University Park, PA (United States); Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)
Publication Date:
Report Number(s):
BNL-114861-2017-JAAM
Journal ID: ISSN 2469-9950; PRBMDO
Grant/Contract Number:
SC0012704; SC0001299/DE-FG02-09ER46577
Type:
Accepted Manuscript
Journal Name:
Physical Review B
Additional Journal Information:
Journal Volume: 96; Journal Issue: 20; Journal ID: ISSN 2469-9950
Publisher:
American Physical Society (APS)
Research Org:
Brookhaven National Laboratory (BNL), Upton, NY (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY
OSTI Identifier:
1425052
Alternate Identifier(s):
OSTI ID: 1406394