Artificial Graphene Spin Polarized Electrode for Magnetic Tunnel Junctions

Area of Science:

• Condensed Matter Physics
• Materials Science
• Spintronics

Background:

• Two-dimensional (2D) materials allow electronic structure manipulation via proximity effects.
• This capability is crucial for engineering 2D interfaces and van der Waals heterostructures for quantum materials and devices.

Purpose of the Study:

• To investigate the creation of an artificial spin-polarized electrode from graphene.
• To utilize proximity interaction with a ferromagnetic insulator for applications in magnetic tunnel junctions (MTJs).

Main Methods:

• Fabrication of ferromagnetic insulator/graphene artificial electrodes.
• Integration of these electrodes into MTJs equipped with spin analyzers.
• Observation and analysis of tunnel magnetoresistance (TMR) to detect spin polarization.

Main Results:

• Successful fabrication and integration of artificial graphene electrodes in MTJs.
• Experimental evidence of emergent spin polarization in graphene layers due to proximity effect, confirmed by TMR.
• Deduced a spin-dependent splitting of graphene's Dirac band structure (approximately 15 meV).

Conclusions:

• The proximity effect can induce significant spin polarization in graphene, paving the way for tunable spintronics.
• This approach demonstrates the potential of 2D quantum materials for advanced spintronic devices, including memory cells and logic circuits.