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Spin polarization in quantum point contact based on wurtzite topological quantum well
Xin Xue1, Fobao Huang2,3, Gongwei Hu4
1Department of Physics, Lvliang University, Lvliang 03300, China.
Physical Chemistry Chemical Physics : PCCP
|September 23, 2023
Summary
This study demonstrates electrical control of spin-polarized electron transport in topological wurtzite quantum wells using a quantum point contact. Adjusting the quantum point contact width tunes spin-orbit coupling, enabling manipulation for spintronics applications.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Quantum Mechanics
Background:
- Wide-gap wurtzite semiconductors are key for high-temperature spintronics.
- Topological insulators in wurtzite quantum wells (QWs) offer platforms for spin-polarized transport via topological edges and Rashba spin-orbit coupling (SOC).
Purpose of the Study:
- To propose and investigate a spin-polarized device in a quantum point contact (QPC) structure based on ZnO/CdO wurtzite topological QWs.
- To explore the manipulation of spin-polarized electron transport through electrical control.
Main Methods:
- Utilized a quantum point contact (QPC) structure within ZnO/CdO wurtzite topological QWs.
- Investigated the quantum size effect on lateral spin-orbit coupling (SOC) and edge state band gaps by varying QPC width.
- Analyzed spin-polarized conductance oscillations and spin precession controlled by split-gate voltage.
Main Results:
- QPC width effectively controls lateral SOC and edge state band gaps via the quantum size effect.
- Spin-polarized conductance exhibits voltage-controlled oscillations due to spin precession.
- QPC-induced spin splitting is highly nonlinear, strengthening near the band gap.
- Spin splitting is suppressed for QPC widths > 50 nm, leading to long spin precession lengths.
Conclusions:
- QPC width-dependent lateral SOC offers an electrical method to manipulate spin-polarized electron transport in topological wurtzite systems.
- This approach is promising for advancing high-temperature spintronics applications.
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