Tunable Spin Injection in High-Quality Graphene with One-Dimensional Contacts

Area of Science:

• Physics
• Materials Science
• Quantum Computing

Background:

• Spintronics utilizes low-dimensional electronic systems for quantum computation.
• Standard 2D tunnel contacts in graphene introduce impurities and doping, hindering spin transport.
• Improving spin transport in graphene is crucial for advanced electronic devices.

Purpose of the Study:

• To demonstrate efficient spin injection and tunable spin signals in encapsulated graphene.
• To overcome limitations of 2D tunnel contacts using novel 1D contacts.
• To enable high-quality graphene channels for spintronics.

Main Methods:

• Fabrication of van der Waals heterostructures with 1D contacts.
• Encapsulation of graphene to minimize impurities.
• Characterization of spin injection and transport properties at room and low temperatures.

Main Results:

• Achieved efficient spin injection and tunable spin signals in fully encapsulated graphene.
• Utilized 1D contacts to prevent graphene channel doping, resulting in high mobilities (up to 130,000 cm² V⁻¹ s⁻¹).
• Observed spin diffusion lengths approaching 20 μm and enhanced spin signals via electrostatic gating.

Conclusions:

• 1D contacts in van der Waals heterostructures offer a promising route for high-performance spintronic devices.
• This architecture enables high-quality graphene channels with tunable spin properties.
• The findings pave the way for advanced quantum computing and spintronic applications.