Molecular Switch by Adsorbing the Au6 Cluster on Single-Walled Carbon Nanotubes: Role of Many-Body Effects of vdW Forces

Advanced molecular switches are essential for constructing the basic components of nanodevices. Herein, a molecular-scale switchable system based on the bistable configurations of the Au-6 cluster on the N-doped single-walled carbon nanotube is proposed by using the density functional theory method with many-body dispersion (MBD) forces. The delicate balance among Pauli repulsion, chemical binding, electrostatic interactions, and MBD forces is found to be critical for achieving this molecular switch, while the many-body effects of dispersion forces are identified to be controllable by the two former interactions. These results demonstrate that chemical binding and Pauli repulsion transform the many-body effects of dispersion forces in low-dimensional adsorption systems from negative to positive, which are adjustable by adsorption distance, atomic volume, and anisotropy as well as adsorption configuration of adsorbates. These findings provide a means for tuning the stability of a given complex and promise a rational design of nanodevices.