Engineering the spin polarization of one-dimensional electrons

Area of Science:

• Condensed Matter Physics
• Spintronics
• Quantum Information Science

Background:

• Spin-orbit interaction (SOI) is crucial for spintronics.
• Controlling electron spin polarization in low-dimensional systems is challenging.
• GaAs-based electron gases are standard platforms for studying quantum phenomena.

Purpose of the Study:

• To demonstrate controlled monitoring of spin polarization in a 1D channel.
• To investigate the effect of spin-polarized electrons on spin-orbit interaction in a 2D electron gas.
• To explore potential applications in spin-engineering and quantum information.

Main Methods:

• Magneto-focusing technique was employed.
• Controlled variation of the effective length of a 1D channel.
• Injection of spin-polarized 1D electrons into a 2D GaAs electron gas.
• Analysis of focusing peak splitting and modulation by in-plane magnetic fields.

Main Results:

• Partial spin polarization of electrons in the 1D channel was achieved and verified.
• Injection of polarized electrons caused a split in odd-focusing peaks in the 2D gas.
• Unpolarized electrons did not affect the focusing spectrum.
• Zeeman energy modulation confirmed spin splitting, indicating direct measurement of spin polarization.

Conclusions:

• The study provides direct evidence of spin polarization measurement within a 1D channel.
• Spin-polarized 1D electrons enhance spin-orbit interaction in the 2D regime.
• Spatial control of spin states and tunable SOI pave the way for advanced spin-engineering and quantum information applications.