Emergence of Interlayer Coherence in Twist-Controlled Graphene Double Layers

Area of Science:

• Condensed Matter Physics
• Materials Science

Background:

• Graphene heterostructures exhibit unique electronic properties influenced by stacking order and twist angle.
• Interlayer coherence in van der Waals heterostructures is a key phenomenon for novel electronic devices.

Purpose of the Study:

• To investigate interlayer tunneling and coherence in twist-controlled double monolayer graphene.
• To explore the role of twist angle in revealing interlayer phase coherence.

Main Methods:

• Fabrication of twist-controlled double monolayer graphene heterostructures.
• Transport measurements in the quantum Hall regime, focusing on zero interlayer bias.
• Analysis of interlayer conductance peaks and linewidth variations.

Main Results:

• Enhanced interlayer tunneling with reduced linewidth observed at zero interlayer bias.
• Stable zero-bias interlayer conductance peaks detected near specific layer filling factors (ν_{T}, ν_{B} ≈ ±1/2, ±3/2) and total filling factors (ν = ±1, ±3).
• Emergence of interlayer phase coherence signaled by conductance peaks.

Conclusions:

• Twist control is a critical factor in observing and understanding interlayer coherence in graphene heterostructures.
• The observed phenomena provide insights into the fundamental physics of layered two-dimensional materials.
• This work paves the way for utilizing twist engineering in designing future electronic devices.