Visualizing quantum modes and designing electronic structure across scales, Part I

Multilayer moiré systems with more than two constituent layers enable a myriad of structural motifs across a wide range of length scales. The incorporation of structure at multiple scales provides unprecedented opportunities to design spatially varying electronic textures, incorporating correlated phases, Chern domains, and superconductivity, among other phases [1-2]. We also know that extrinsic confinement--traditionally from electrostatic potential or scattering centers--can create emergent structure in electronic wavefunctions that depends both on the geometry and the type of confinement. In this work, we ask how confinement arises from intrinsic structural variations in multilayer moiré systems. We focus on minimally twisted monolayer-bilayer graphene as a model system with 50nm to 150nm triangular domains of Bernal and rhombohedral trilayer graphene. In the first part of this talk, we use low-temperature conductive AFM as a spectroscopic imaging tool to investigate the confinement of electronic modes that occurs both at domain walls and within domains themselves. We discuss implications for the interplay between electronic phases and atomic structure in multilayer twisted graphene systems in general, which will be expanded in Part II.

 

[1] Yang, et al, Phys. Rev. B 110, 115434 (2024).

[2] Uri, et al, Nature 620, 762 (2023).