We review recent progresses in the study of flat band systems, especially focusing on the
fundamental physics related to the singularity of the flat band's Bloch wave functions. We first …

The introduction of the concept of topology into condensed matter physics has greatly
deepened our fundamental understanding of transport properties of electrons as well as all …

Topological electronic flattened bands near or at the Fermi level are a promising route
towards unconventional superconductivity and correlated insulating states. However, the …

By tuning the angle between graphene layers to specific “magic angles” the lowest energy
bands of twisted bilayer graphene (TBLG) can be made flat. The flat nature of the bands …

In flat bands, superconductivity can lead to surprising transport effects. The superfluid
“mobility”, in the form of the superfluid weight D s, does not draw from the curvature of the …

We study the electronic structures and topological properties of (M+ N)-layer twisted
graphene systems. We consider the generic situation that N-layer graphene is placed on top …

Semiclassical quantization of electronic states under a magnetic field, as proposed by
Onsager, describes not only the Landau level spectrum but also the geometric responses of …

We show that a quantum scar state, an atypical eigenstate breaking eigenstate
thermalization hypothesis embedded in a many-body energy spectrum, can be constructed …

The recent realization of twisted, two-dimensional, bilayers exhibiting strongly correlated
states has created a platform in which the relation between the properties of the electronic …

Flat bands (FBs), presenting a strongly interacting quantum system, have drawn increasing
interest recently. However, experimental growth and synthesis of FB materials have been …