Strain effects on the electronic properties in δ -doped oxide superlattices
Abstract
We investigated strain effects on the electronic properties of (LaTiO3)1/(SrTiO3)N superlattices using density functional theory. Under biaxial in-plane strain within the range of -5% ≤ ε// ≤ 5%, the dxy orbital electrons are highly localized at the interfaces whereas the dyz and dxz orbital electrons are more distributed in the SrTiO3 (STO) spacer layers. For STO thickness N ≥ 3 unit cells (u.c.), the dxy 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 dxy orbital, the dyz 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 dxy orbital and the dyz and dxz orbitals respond to biaxial in-plane strain in an opposite way, the transport dimensionality of the majority carriers can be controlled between 2D and 3D by applying biaxial in-plane strain.
- Authors:
-
- Southern Methodist Univ., Dallas, TX (United States). Dept. of Mechanical Engineering
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science & Technology Division
- Publication Date:
- Research Org.:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- Sponsoring Org.:
- USDOE Office of Science (SC), Basic Energy Sciences (BES)
- OSTI Identifier:
- 1185729
- Grant/Contract Number:
- AC05-00OR22725
- Resource 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
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; oxide superlattice; LTO/STO heterostructure; electronic reconstruction
Citation Formats
You, Jeong Ho, Lee, Jun Hee, Okamoto, Satoshi, Cooper, Valentino, and Lee, Ho Nyung. Strain effects on the electronic properties in δ -doped oxide superlattices. United States: N. p., 2015.
Web. doi:10.1088/0022-3727/48/8/085303.
You, Jeong Ho, Lee, Jun Hee, Okamoto, Satoshi, Cooper, Valentino, & Lee, Ho Nyung. Strain effects on the electronic properties in δ -doped oxide superlattices. United States. https://doi.org/10.1088/0022-3727/48/8/085303
You, Jeong Ho, Lee, Jun Hee, Okamoto, Satoshi, Cooper, Valentino, and Lee, Ho Nyung. Sat .
"Strain effects on the electronic properties in δ -doped oxide superlattices". United States. https://doi.org/10.1088/0022-3727/48/8/085303. https://www.osti.gov/servlets/purl/1185729.
@article{osti_1185729,
title = {Strain effects on the electronic properties in δ -doped oxide superlattices},
author = {You, Jeong Ho and Lee, Jun Hee and Okamoto, Satoshi and Cooper, Valentino and Lee, Ho Nyung},
abstractNote = {We investigated strain effects on the electronic properties of (LaTiO3)1/(SrTiO3)N superlattices using density functional theory. Under biaxial in-plane strain within the range of -5% ≤ ε// ≤ 5%, the dxy orbital electrons are highly localized at the interfaces whereas the dyz and dxz orbital electrons are more distributed in the SrTiO3 (STO) spacer layers. For STO thickness N ≥ 3 unit cells (u.c.), the dxy 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 dxy orbital, the dyz 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 dxy orbital and the dyz and dxz orbitals respond to biaxial in-plane strain in an opposite way, the transport dimensionality of the majority carriers can be controlled between 2D and 3D by applying biaxial in-plane strain.},
doi = {10.1088/0022-3727/48/8/085303},
journal = {Journal of Physics. D, Applied Physics},
number = 8,
volume = 48,
place = {United States},
year = {Sat Feb 07 00:00:00 EST 2015},
month = {Sat Feb 07 00:00:00 EST 2015}
}
Web of Science