Band structure engineering of 2D materials using moiré ferroelectrics

Superlattice formation in real space develops a folded band structure in the reciprocal space in solids. Such superlattice has been achieved in various van der Waals heterostructures using a moiré pattern formed by stacking materials with different lattice constants, or by twisting two layers. The dramatic modification of the band structure has led to the discovery of various intriguing electronic phases. Here, we introduce a new approach for engineering the band structure using moiré ferroelectrics. Different from twisted bilayer graphene, twisted bilayer boron nitride is characterized by the local inversion symmetry breaking with ferroelectric polarization [1-3]. Thus, the moiré pattern is associated with the triangular network of alternating out-of-plane electric dipole moment. We study the proximity effect of the moiré ferroelectrics to the 2D materials to demonstrate its potential for band structure modification in arbitrary materials.

 

[1] C. R. Woods et al., Nat. Commun. 12, 347 (2021).

[2] K. Yasuda et al., Science 372, 1458–1462 (2021).

[3] M. V. Stern et al., Science 372, 1462–1466 (2021).