Pressure Engineering of Effective Magic Angles in Twisted Bilayer Graphene

Twisted bilayer graphene (tBLG) has emerged these years with the growing research interests in the strongly correlated insulating phase, unconventional superconducting transition, and their tunable electronic properties. Hydrostatic pressure can effectively modulate the interlayer interactions in tBLG, thereby altering its electronic band structure and related physical properties. Herein, a pressure-engineering strategy has been developed to regulate the carrier transport behavior of a 2D tBLG nanodevice, fabricated via our established approach for in situ electrical measurements under high pressure. The obtained electrical results revealed that the tBLG (twist angle 1.3 ± 0.1°) device presented semiconducting behavior under different pressures. The strongly correlated state emerged in tBLG under hole doping within a rather narrow pressure window (∼4.1 GPa). Additionally, the extracted activation energy reached a maximum around 2.0 GPa. These findings provide valuable insights into pressure-tuned effective magic angle and further delving into the electronic properties of 2D twisted electronic systems.