Computational Design of Moiré Assemblies aided by Artificial Intelligence
ORAL
Abstract
Two-dimensional (2D) layered materials offer a materials platform with potential applications from energy to information processing devices. Although some single- and few-layer forms of materials such as graphene and transition metal dichalcogenides have been realized and thoroughly studied, the space of arbitrary layered assemblies is still mostly unexplored. The main goal of this work is to demonstrate precise control of layered materials' electronic properties through careful choice of the constituent layers, their stacking, and relative orientation. Physics-based and AI-driven approaches for the automated planning, execution, and analysis of electronic structure calculations are applied to layered assemblies based on prototype one-dimensional (1D) materials and realistic 2D materials. We find it is possible to routinely generate moiré band structures in 1D with desired electronic characteristics such as a bandgap of any value within a large range, even with few layers and materials (here, four and six, respectively). We argue that this tunability extends to 2D materials by showing the essential physical ingredients are already evident in calculations of two-layer MoS2 and multi-layer graphene moiré assemblies.
*The authors acknowledge Efthimios Kaxiras and Pavlos Protopapas at Harvard University for stimulating discussions. Electronic structure calculations were performed on XSEDE, supported by NSF Grant No. ACI-1548562. Models were trained on the Cannon cluster, supported by the FAS Division of Science Research Computing Group at Harvard University. We relied on computational resources of NERSC, a DOE facility operated under Contract No. DE-AC02-05CH11231. This work was supported in part by DOE Office of Science (Basic Energy Sciences; BES) under Award No. DE-SC0019300 by NSF Grant Nos. OIA-1921199 and DMR-1231319 (Science and Technology Center on Integrated Quantum Materials, CIQM), and by the São Paulo Research Foundation (FAPESP) under Grant No. 17/18139-6.