Twisting nanoporous graphene on graphene: electronic decoupling and chiral currents

Area of Science:

• Condensed matter physics
• Materials science
• Nanotechnology

Background:

• Nanoporous graphene (NPG) offers potential for nanoscale electron transport control.
• Integrating NPG with substrates is crucial for preserving its anisotropic properties.
• Graphene is a promising substrate due to its unique electronic characteristics.

Purpose of the Study:

• To investigate the electronic coupling between NPG and a graphene substrate.
• To understand how interlayer twist angle influences electron transport in NPG/graphene heterostructures.
• To identify methods for probing twist-angle-dependent coupling.

Main Methods:

• Atomistic tight-binding model.
• Non-equilibrium Green's functions (NEGF) formalism.
• Simulations of electron transport through NPG/graphene bilayers.

Main Results:

• Electronic coupling is modulated by the interlayer twist angle.
• Small twist angles (θ ≲ 10°) induce strong hybridization, significant interlayer transmission, and Talbot-like interference.
• Chiral current features emerge due to twist-induced symmetry breaking.
• Increasing twist angle weakens coupling, restoring monolayer properties.

Conclusions:

• The twist angle is a critical parameter for tuning electronic transport in NPG/graphene systems.
• Chiral electron transport can be engineered by controlling the twist angle.
• Scanning tunneling microscopy can probe twist-dependent interlayer coupling.