Single-Electron Transistor Based on Quantum Dots in Twisted Graphene/Hexagonal Boron Nitride Bilayer Heterostructure

TL;DR

This paper explores how twisted graphene and hexagonal boron nitride can be used to create efficient single-electron transistors with tunable properties.

Contribution

The study introduces a design principle for single-electron transistors using twisted 2D heterostructures with controllable size, stacking, and twist angle.

Findings

Quantum dot size and stacking configuration most strongly influence charge stability and transport.

Twist angle allows precise control of charge states in single-electron transistors.

AA-stacked devices show twist-angle-dependent conductance peak shifts due to atomic registry.

Abstract

Twisted graphene/hexagonal boron nitride (TG/hBN) bilayers, with their tunable moiré potential and atomically clean interfaces, offer an ideal platform for high-performance single-electron transistors (SET). Combining quantum transport simulations with first-principles calculations, we systematically investigate how stackings (AA, AB, BA), twist angles, quantum dot sizes, and gate-island coupling jointly modulate SET performance. Our central finding reveals a clear hierarchy: quantum dot size and stacking configuration dominate charge stability and transport, while twist angle introduces precise control of charge state. All stackings exhibit sharp, symmetric Coulomb blockade peaks, confirming stable single-electron tunneling, and gate coupling remains highly linear across parameters. Strikingly, only AA-stacked devices show a systematic twist-angle-dependent shift in conductance peaks, a direct signature of its perfect atomic registry and extreme angular sensitivity. This work establishes an idealized “size-, stacking-, and twist-angle modulation” design principle and theoretical roadmap based on TG/hBN, providing fundamental insights for future experimental exploration of tunable, low-noise quantum-electronic devices from twisted 2D heterostructures.

Figures