Pressure-induced flat bands in one-dimensional moir superlattices of collapsed chiral carbon nanotubes

Two-dimensional (2D) moire superlattices have been extensively investigated, whereas the one-dimensional (1D) moire superlattices have remained largely unexplored, due to the difficulty in achieving 1D moire superlattices experimentally. Recent theoretical studies have predicted that certain collapsed chiral carbon nanotubes (CNTs) behave as 1D moire superlattices with novel strongly correlated physics, owing to the emergence of 1D flat bands. However, the realization of 1D flat bands is limited to CNTs with a narrow range of chirality, which hinders the experimental investigation. Here, using molecular dynamics simulations and tight-binding calculations, we reveal that the application of external pressure can induce 1D moire flat bands in a wide range of collapsed CNTs of both metallic and semiconducting types. We further provide a comprehensive analysis of the emergence of the 1D flat bands, and derive critical pressures for CNTs of various chiralities. Our study presents a versatile approach for creating 1D flat bands, and therefore could greatly facilitate the experimental exploration of 1D strongly correlated physics in collapsed CNT moire superlattices.