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Title: Strain effects on the electronic properties in δ -doped oxide superlattices

We investigated strain effects on the electronic properties of (LaTiO 3) 1/(SrTiO 3)N superlattices using density functional theory. Under biaxial in-plane strain within the range of -5% ≤ ε// ≤ 5%, the d xy orbital electrons are highly localized at the interfaces whereas the d yz and d xz orbital electrons are more distributed in the SrTiO 3 (STO) spacer layers. For STO thickness N ≥ 3 unit cells (u.c.), the d xy orbital electrons form two-dimensional (2D) electron gases (2DEGs). The quantized energy levels of the 2DEG are insensitive to the STO spacer thickness, but are strongly dependent on the applied biaxial in-plane strain. As the in-plane strain changes from compressive to tensile, the quantized energy levels of the dxy orbitals decrease thereby creating more states with 2D character. In contrast to the d xy orbital, the d yz and dxz orbitals always have three-dimensional (3D) transport characteristics and their energy levels increase as the strain changes from compressive to tensile. In conclusion, since the charge densities in the d xy orbital and the d yz and d xz orbitals respond to biaxial in-plane strain in an opposite way, the transport dimensionality of the majority carriers can be controlledmore » between 2D and 3D by applying biaxial in-plane strain.« less
Authors:
 [1] ;  [2] ;  [2] ;  [2] ;  [2]
  1. Southern Methodist Univ., Dallas, TX (United States). Dept. of Mechanical Engineering
  2. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science & Technology Division
Publication Date:
Grant/Contract Number:
AC05-00OR22725
Type:
Accepted Manuscript
Journal Name:
Journal of Physics. D, Applied Physics
Additional Journal Information:
Journal Volume: 48; Journal Issue: 8; Journal ID: ISSN 0022-3727
Publisher:
IOP Publishing
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:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; oxide superlattice; LTO/STO heterostructure; electronic reconstruction
OSTI Identifier:
1185729