Recent research published by the CMT group in collaboration with Rutgers University uncover a novel way of achieving flat bands in through strain superlattices.
An international team led by researchers at Rutgers University in the US has found a way to create “flat? electronic bands - that is, electron states in which there is no relationship between the electrons’ energy and velocity - in graphene simply by causing the material to buckle. This new strategy could be used to produce so-called “superlattice? systems that serve as platforms for exploring the collective behaviour of electrons in strongly-interacting quantum systems. Such behaviour is known to be linked to high-temperature superconductivity, but a complete understanding is still lacking.
Flat bands are especially interesting for physicists because electrons become “dispersionless? in these bands - that is, their kinetic energy is suppressed. As the electrons slow down almost to a halt, their effective mass approaches infinity, leading to exotic topological phenomena as well as strongly-correlated states of matter associated with high-temperature superconductivity, magnetism and other quantum properties of solids.
Physics World (7 Sept 2020)
Evidence of flat bands and correlated states in buckled graphene superlattices
Jinhai Mao, Slaviša P. Milovanovi’, Miša An?elkovi’, Xinyuan Lai, Yang Cao, Kenji Watanabe, Takashi Taniguchi, Lucian Covaci, Francois M. Peeters, Andre K. Geim, Yuhang Jiang & Eva Y. Andrei
Nature 584, 215 (2020)