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Title: Van der Waals engineering of ferromagnetic semiconductor heterostructures for spin and valleytronics

The integration of magnetic material with semiconductors has been fertile ground for fundamental science as well as of great practical interest toward the seamless integration of information processing and storage. We create van der Waals heterostructures formed by an ultrathin ferromagnetic semiconductor CrI 3 and a monolayer of WSe 2. We observe unprecedented control of the spin and valley pseudospin in WSe 2, where we detect a large magnetic exchange field of nearly 13 T and rapid switching of the WSe 2 valley splitting and polarization via flipping of the CrI 3 magnetization. The WSe2 photoluminescence intensity strongly depends on the relative alignment between photoexcited spins in WSe 2 and the CrI 3 magnetization, because of ultrafast spin-dependent charge hopping across the heterostructure interface. The photoluminescence detection of valley pseudospin provides a simple and sensitive method to probe the intriguing domain dynamics in the ultrathin magnet, as well as the rich spin interactions within the heterostructure.
Authors:
 [1] ;  [1] ;  [1] ;  [2] ;  [2] ;  [1] ;  [1] ;  [3] ;  [3] ;  [4] ;  [5] ;  [5] ;  [1] ;  [1]
  1. Univ. of Washington, Seattle, WA (United States)
  2. Carnegie Mellon Univ., Pittsburgh, PA (United States)
  3. National Inst. for Materials Science (NIMS), Tsukuba (Japan)
  4. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
  5. Univ. of Hong Kong (China)
Publication Date:
Grant/Contract Number:
AC05-00OR22725
Type:
Accepted Manuscript
Journal Name:
Science Advances
Additional Journal Information:
Journal Volume: 3; Journal Issue: 5; Journal ID: ISSN 2375-2548
Publisher:
AAAS
Research Org:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS
OSTI Identifier:
1376521