Interlayer electron flow and field shielding in twisted trilayer graphene quantum dots.

Area of Science:

• Condensed Matter Physics
• Materials Science
• Nanotechnology

Background:

• Multilayer graphene (MLG) shows high intralayer electron mobility but variable interlayer electrical conductance.
• Interlayer electron flow in MLG is crucial for electronic devices and tunable via stacking, distance, disc size, and electric field.
• Polarizability quantifies electronic response to external fields, essential for understanding electron rearrangement.

Purpose of the Study:

• To develop a polarizability decomposition scheme to isolate inter- and intra-layer contributions in twisted trilayer graphene (TTG) quantum dots.
• To analyze charge transfer (CT) and field shielding effects influencing interlayer electron flow.
• To investigate the modulation of vertical conductivity in TTG quantum dots by controlling structural parameters.

Main Methods:

• Utilized a first-principles approach to compute field-induced electron density variations.
• Developed a polarizability decomposition scheme to distinguish inter- and intra-layer contributions.
• Analyzed the impact of twist angle and disc size on CT and shielding effects.

Main Results:

• The scheme successfully isolates inter- and intra-layer polarizability, reflecting charge transfer and field shielding.
• The middle layer in TTG plays a key role in facilitating interlayer electron flow.
• Significant CT and shielding effects were observed in both Bernal stacking and structures with small twist angles from AAA stacking.
• Inter- and intra-layer effects were found to vary with twist angle and disc size, enabling controllable conductive/dielectric conversion.

Conclusions:

• The developed scheme provides precise control over interlayer conductance in TTG quantum dots.
• Understanding inter- and intralayer polarizability is vital for designing and manipulating MLG-based electronic devices.
• This work offers insights into tailoring vertical conductivity for novel electronic applications.