Tuning superconductivity in twisted bilayer graphene

Understand

Materials with flat electronic bands often exhibit exotic quantum phenomena owing to strong correlations.

• Remarkably, an isolated low-energy flat band can be induced in bilayer graphene by simply rotating the layers to 1.1$^{\circ}$, resulting in the appearance of gate-tunable superconducting and correlated insulating phases.
• Here, we demonstrate that in addition to the twist angle, the interlayer coupling can also be modified to precisely tune these phases.
• We establish the capability to induce superconductivity at a twist angle larger than 1.1$^{\circ}$ $-$ in which correlated phases are otherwise absent $-$ by varying the interlayer spacing with hydrostatic pressure.