Voltage-controllable spin beam splitter based on realistic magnetic-barrier nanostructure

Area of Science:

• Condensed matter physics
• Spintronics
• Nanotechnology

Background:

• The Goos-Hänchen (GH) effect describes the transverse spatial shift of reflected or transmitted beams.
• Spin electron beams are crucial for spintronics applications, requiring efficient manipulation and injection.
• Magnetic-barrier (MB) nanostructures offer potential for controlling electron spin properties.

Purpose of the Study:

• To theoretically investigate the GH effect of spin electron beams in realistic MB nanostructures.
• To explore the influence of applied voltage on spin polarization within these nanostructures.
• To assess the potential of MB nanostructures for spin injection and beam splitting.

Main Methods:

• Numerical calculation of GH shifts for spin electron beams using the stationary phase method.
• Simulation performed for the InAs material system.
• Investigation of nanostructures created by lithographic patterning of ferromagnetic (FM) or superconducting films.

Main Results:

• Significant spin polarization induced by MB nanostructures with symmetric magnetic field profiles.
• Magnitude and sign of spin polarization are tunable by the electric barrier (EB) created by applied voltage.
• Demonstration of voltage-dependent control over spin polarization.

Conclusions:

• MB nanostructures provide an effective platform for inducing and controlling spin polarization in electron beams.
• These findings suggest a novel approach for spin injection into semiconductors.
• The studied nanostructures can function as voltage-tunable spin beam splitters, advancing spintronic device capabilities.