Flat band, tunable chiral anomaly and pitchfork bifurcation in a honeycomb lattice

Abstract

The search for energy efficient materials is urged not only by the needs of modern electronics but also by emerging applications in neuromorphic computing. Chiral anomaly engineering has established as one of the mechanisms for achieving energy efficient dissipationless transport. Here we show how to design tunable chiral anomalies in a honeycomb lattice without any magnetic fields. Breaking the usual assumption of commensurability and applying an external electric field to a flat band material, we generate electronic modes exhibiting chiral anomalies capable of disorder resilient transport in the bulk of the material, rather than on the edge. As the electric field increases, the system exhibits an unusual cubic-like dispersion. While providing a performance comparable to other known honeycomb lattice-based ballistic conductors such as armchair nanotube, zigzag nanoribbon and hypothetical cumulenic carbyne, this scheme provides routes to strongly correlated localization due to its flat band and exotic cubic dispersion featuring a critical slowing down and pitchfork bifurcation phenomena. These results open a new research avenue for the design of energy efficient information processing and higher-order dispersion materials.