# Observation of drastic electronic structure change in one-dimensional moir\'e crystals

## TL;DR

This study provides the first experimental evidence of strong intertube coupling effects in one-dimensional moiré superlattices formed by double-wall carbon nanotubes, revealing significant changes in optical spectra due to moiré pattern formation.

## Contribution

It demonstrates the first direct experimental observation of drastic electronic structure changes caused by moiré superlattices in one-dimensional nanotube systems.

## Key findings

- Observation of a drastic change in optical transition spectra in specific DWCNTs
- Correlation of spectral changes with strong intertube coupling effects
- Numerical simulations support experimental results

## Abstract

We report the first experimental observation of strong coupling effect in one-dimensional moir\'e crystals. We study one-dimensional double-wall carbon nanotubes (DWCNTs) in which van der Waals-coupled two single nanotubes form one-dimensional moir\'e superlattice. We experimentally combine Rayleigh scattering spectroscopy and electron beam diffraction on the same individual DWCNTs to probe the optical transitions of structure-identified DWCNTs in the visible spectral range. Among more than 30 structure-identified DWCNTs examined, we experimentally observed and identified a drastic change of optical transition spectrum in DWCNT with chirality (12,11)@(17,16). The origin of the marked change is attributed to the strong intertube coupling effect in a moir\'e superlattice formed by two nearly-armchair nanotubes. Our numerical simulation is consistent to these experimental findings.

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Source: https://tomesphere.com/paper/1906.09421