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Updated: Jun 21, 2025
13:56
Probe Type II Band Alignment in One-Dimensional Van Der Waals Heterostructures Using First-Principles Calculations
Published on: October 12, 2019
7.6K
Rashba splitting in polar-nonpolar sandwich heterostructure: a DFT study.
Sanchari Bhattacharya1, Sanjoy Datta1
1Department of Physics and Astronomy, National Institute of Technology, Rourkela 769008, Odisha, India.
Summary
Density functional theory reveals spin-orbit effects in LaAlO3/SrTiO3/LaAlO3 heterostructures. It shows orbital ordering differences at interfaces and significant inter-orbital coupling, impacting Rashba splitting.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Computational Physics
Background:
- Polar-nonpolar oxide heterostructures like LaAlO3/SrTiO3/LaAlO3 exhibit complex electronic properties at interfaces.
- Understanding the electronic structure, particularly the Ti-3d bands and orbital ordering, is crucial for device applications.
- Spin-orbit coupling (SOC) is known to influence electronic band structures, but its specific role in these sandwich systems requires detailed investigation.
Purpose of the Study:
- To investigate the spin-orbit effects on the electronic structure of the LaAlO3/SrTiO3/LaAlO3 sandwich heterostructure.
- To analyze the orbital ordering of the SrTiO3-t2g and eg orbitals near both n-type and p-type interfaces.
- To explore the phenomenon of inter-orbital coupling between t2g and eg orbitals in the presence of SOC.
Main Methods:
- Employed density functional theory (DFT) based first-principles calculations.
- Focused analysis on the Ti-3d bands and their orbital ordering.
- Investigated the influence of spin-orbit coupling (SOC) on the electronic structure and orbital interactions.
Main Results:
- Observed inverted ordering of SrTiO3-t2g orbitals near the n-type interface, consistent with prior experimental work.
- Found natural orbital ordering near the p-type interface, influenced by crystal field splitting.
- Revealed significant inter-orbital coupling between t2g and eg orbitals in the tetragonal slab due to SOC, a novel finding for SrTiO3-based 2D systems.
- Reported that cubic Rashba splitting exceeds linear Rashba splitting, contrary to some experimental observations.
Conclusions:
- The study provides a detailed first-principles understanding of spin-orbit effects in LaAlO3/SrTiO3/LaAlO3 heterostructures.
- Highlights the distinct orbital ordering at n-type and p-type interfaces and the crucial role of SOC in inducing inter-orbital coupling.
- Contributes to a refined understanding of Rashba splitting mechanisms in oxide heterostructures, emphasizing the importance of orbital mixing.
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