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Anisotropic modification of the effective hole g factor by electrostatic confinement
S P Koduvayur1, L P Rokhinson, D C Tsui
1Department of Physics, Purdue University, West Lafayette, Indiana 47907, USA. sunanda@purdue.edu
Physical Review Letters
|June 4, 2008
Summary
Lateral confinement significantly boosts spin splitting anisotropy in 2D hole gases on [311] GaAs. This effect shows distinct behaviors based on confinement direction and magnetic field orientation, linked to spin-orbit interactions.
Area of Science:
- Condensed matter physics
- Semiconductor spintronics
- Low-dimensional electronic systems
Background:
- Two-dimensional hole gases (2DHGs) exhibit complex spin properties influenced by confinement and material structure.
- Anisotropy in spin splitting is crucial for understanding spintronic device functionalities.
- GaAs-based heterostructures provide a versatile platform for exploring quantum phenomena.
Purpose of the Study:
- To investigate the impact of lateral confinement on spin splitting in 2D hole gases.
- To analyze the anisotropy of spin splitting concerning confinement directions and magnetic field orientations.
- To explore the relationship between spin-orbit interactions and observed spin splitting behaviors.
Main Methods:
- Fabrication of 2D hole gases on [311] GaAs substrates with lateral confinement.
- Experimental measurements of energy level spin splitting under varying magnetic fields.
- Analysis of the effective g factor and spin-split plateau characteristics.
Main Results:
- Lateral confinement enhances the anisotropy of spin splitting for both confining directions.
- The effective g factor shows no dependence on 1D energy level number (N) for B || [011], but strong N dependence for B || [233].
- Qualitative differences in spin-split plateaus, including nonquantized ones for [011] confinement, are observed and linked to anisotropic spin-orbit interactions.
Conclusions:
- Lateral confinement plays a critical role in modulating spin splitting anisotropy in 2DHGs.
- The observed differences in spin splitting behavior are directly associated with the anisotropic nature of spin-orbit interactions.
- These findings offer insights into controlling spin properties in semiconductor nanostructures for spintronic applications.
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