Certain lattice wave systems in translationally invariant settings have one or more spectral
bands that are strictly flat or independent of momentum in the tight binding approximation …

Borophene, a 2D allotrope of boron and the lightest elemental Dirac material, is the latest
very promising 2D material owing to its unique structural and electronic characteristics of the …

Discovery of robust yet reversibly switchable electric dipoles at reduced dimensions is
critical to the advancement of nanoelectronics devices. Energy bands flat in momentum …

Quasi‐2D semiconductors have garnered immense research interest for next‐generation
electronics and thermoelectrics due to their unique structural, mechanical, and transport …

Electronic flat-band materials host quantum states characterized by a quenched kinetic
energy. These flat bands are often conducive to enhanced electron correlation effects and …

Flat bands (FBs) can appear in two‐dimensional (2D) geometrically frustrated systems
caused by quantum destructive interference (QDI). However, the scarcity of pure 2D …

Exotic quantum phenomena may appear in material systems with multiple orders or phases,
where the mutual interactions can give rise to new physics beyond that of each component …

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 …

Kagome materials have emerged as a setting for emergent electronic phenomena that
encompass different aspects of symmetry and topology. It is debated whether the XV6Sn6 …

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 …