Observation of bandgaps in multilayer silicon nanoribbons

One-dimensional (1D) materials have attracted significant interest due to their unique quantum properties and potential applications in nanoscale devices. Pentagonal silicon nanoribbons (SiNRs), a prototypical 1D material, have been recently reported to host gapless Dirac fermions. However, for practical applications such as logic devices, the realization of a bandgap is highly desirable. In this work, we investigate the electronic structure of multilayer SiNRs grown on Ag(110) using angle-resolved photoemission spectroscopy. Our measurements reveal the emergence of a large bandgap at the Dirac point in these multilayer structures. Tight-binding model analyses suggest that the bandgap arises from the long-range periodicity along the nanoribbon chains. These findings demonstrate that multilayer SiNRs represent a novel phase of elemental silicon and provide a promising platform for engineering bandgaps in 1D materials, with potential applications in quantum and electronic devices.