Abstract

Superlattice engineering in van der Waals heterostructures (e. g. by moiré engineering) provides a powerful platform for designing electronic bands and realising correlated and topological quantum phenomena. Here, we pioneer a scheme to tailor superpotentials based on intrinsic substrate electronic orders. We show that this establishes a robust, self-aligned, and highly versatile route to band-structure control as we demonstrate in graphene by engineering two distinct, nearly commensurate superlattices using the charge density waves of 1T-NbSe2. In these superlattices the graphene’s Dirac cones are folded either to the Γ-point or to the K-points of the mini-Brillouin zone. Using scanning tunnelling microscopy, we observe that the Γ-folded system preserves C₃ symmetry, while the K-folded system exhibits spontaneous symmetry breaking. Combining density functional theory with an interlayer interaction model, we reveal that this difference is not electronically driven but originates from a structural instability. Our work establishes superlattice engineering for designer quantum states and unveils a structural mechanism for controlled emergent symmetry breaking.

Abstract

Superlattice engineering in van der Waals heterostructures (e. g. by moiré engineering) provides a powerful platform for designing electronic bands and realising correlated and topological quantum phenomena. Here, we pioneer a scheme to tailor superpotentials based on intrinsic substrate electronic orders. We show that this establishes a robust, self-aligned, and highly versatile route to band-structure control as we demonstrate in graphene by engineering two distinct, nearly commensurate superlattices using the charge density waves of 1T-NbSe2. In these superlattices the graphene’s Dirac cones are folded either to the Γ-point or to the K-points of the mini-Brillouin zone. Using scanning tunnelling microscopy, we observe that the Γ-folded system preserves C₃ symmetry, while the K-folded system exhibits spontaneous symmetry breaking. Combining density functional theory with an interlayer interaction model, we reveal that this difference is not electronically driven but originates from a structural instability. Our work establishes superlattice engineering for designer quantum states and unveils a structural mechanism for controlled emergent symmetry breaking.

Abstract

Superlattice engineering in van der Waals heterostructures (e. g. by moiré engineering) provides a powerful platform for designing electronic bands and realising correlated and topological quantum phenomena. Here, we pioneer a scheme to tailor superpotentials based on intrinsic substrate electronic orders. We show that this establishes a robust, self-aligned, and highly versatile route to band-structure control as we demonstrate in graphene by engineering two distinct, nearly commensurate superlattices using the charge density waves of 1T-NbSe2. In these superlattices the graphene’s Dirac cones are folded either to the Γ-point or to the K-points of the mini-Brillouin zone. Using scanning tunnelling microscopy, we observe that the Γ-folded system preserves C₃ symmetry, while the K-folded system exhibits spontaneous symmetry breaking. Combining density functional theory with an interlayer interaction model, we reveal that this difference is not electronically driven but originates from a structural instability. Our work establishes superlattice engineering for designer quantum states and unveils a structural mechanism for controlled emergent symmetry breaking.

Abstract

Superlattice engineering in van der Waals heterostructures (e. g. by moiré engineering) provides a powerful platform for designing electronic bands and realising correlated and topological quantum phenomena. Here, we pioneer a scheme to tailor superpotentials based on intrinsic substrate electronic orders. We show that this establishes a robust, self-aligned, and highly versatile route to band-structure control as we demonstrate in graphene by engineering two distinct, nearly commensurate superlattices using the charge density waves of 1T-NbSe2. In these superlattices the graphene’s Dirac cones are folded either to the Γ-point or to the K-points of the mini-Brillouin zone. Using scanning tunnelling microscopy, we observe that the Γ-folded system preserves C₃ symmetry, while the K-folded system exhibits spontaneous symmetry breaking. Combining density functional theory with an interlayer interaction model, we reveal that this difference is not electronically driven but originates from a structural instability. Our work establishes superlattice engineering for designer quantum states and unveils a structural mechanism for controlled emergent symmetry breaking.