Single electron transistor based on twisted bilayer graphene quantum dots

Abstract

Electrical properties of twisted bilayer graphene exhibit angle-dependent characteristics, sparking a thriving development in the field of twistronics. However, the application of quantum dots (QDs) made of twisted bilayer graphene in single-electron transistors (SETs) remains largely unexplored so far. We here investigate the electronic properties of twisted bilayer graphene QDs (TBG QDs) within a SET configuration. We compare the performance of conventional and double-gated SET structures and find that the double-gated configuration provides enhanced control over the electronic properties of TBG QDs. We analyze the influence of rotation angles on the charge stability diagrams and observe that the linear and quadratic gate-island coupling strengths generally decrease as the rotation angle decreases. Furthermore, we quantify the effect of QD size on the charge stability diagrams and find that the size of the diamond-shaped regions decreases as the TBG QD size increases. Results presented herein may help pave the way for realization and application of TBG QDs based SET.