Unconventional non-local relaxation dynamics in a twisted trilayer graphene moiré superlattice

• DOI: 10.1038/s41467-022-35213-5
• Publication Date: 2022-12-08T20:04:54Z
• Authors: Dorri Halbertal; Simon Turkel; Christopher J. Ci...; Jonas B. Profe; Nathan Finney; Valerie Hsieh; Kenji Watanabe; Takashi Taniguchi; James Hone; Cory Dean; Prineha Narang; Abhay N. Pasupathy; Dante M. Kennes; D. N. Basov
• Keywords: 0301 basic medicine; Condensed Matter - Materials Science; 0303 health sciences; Condensed Matter - Mesoscale and Nanoscale Physics; Science; Q; Materials Science (cond-mat.mtrl-sci); FOS: Physical sciences; 530; Article; 03 medical and health sciences; Mesoscale and Nanoscale Physics (cond-mat.mes-hall); info:eu-repo/classification/ddc/500

AbstractThe electronic and structural properties of atomically thin materials can be controllably tuned by assembling them with an interlayer twist. During this process, constituent layers spontaneously rearrange themselves in search of a lowest energy configuration. Such relaxation phenomena can lead to unexpected and novel material properties. Here, we study twisted double trilayer graphene (TDTG) using nano-optical and tunneling spectroscopy tools. We reveal a surprising optical and electronic contrast, as well as a stacking energy imbalance emerging between the moiré domains. We attribute this contrast to an unconventional form of lattice relaxation in which an entire graphene layer spontaneously shifts position during assembly, resulting in domains of ABABAB and BCBACA stacking. We analyze the energetics of this transition and demonstrate that it is the result of a non-local relaxation process, in which an energy gain in one domain of the moiré lattice is paid for by a relaxation that occurs in the other.