Giant Switching Effect and Spintronic Transport Properties in Cyclo[18]carbon‐Based Molecular Devices

Abstract

The isolated cyclo[18]carbon (C18), as a newly synthesized carbon allotrope, has potential to become the core unit of high‐end electronic devices due to its excellent physical properties. However, the research on C18 in molecular devices is still in the rudimentary stage. Herein, a novel molecular spin‐filtering device, formed by covalently sandwiching a C18 ring between two zigzag‐edged graphene nanoribbons (ZGNRs), is investigated based on the nonequilibrium Green's function method and density functional theory. It is found that the spin‐polarized current can be implemented and controlled through adjusting the magnetic configuration of left (right) electrode. Remarkably, a strong bimolecular configuration switching effect can be achieved by inserting a metal carbon chain between nonmagnetic ZGNRs and C18 (on/off ratio of ≈2737). The results suggest theoretical guidance for the design of next‐generation carbon‐based molecular spintronic devices.