English
Related papers

Related papers: General construction of flat bands with and withou…

200 papers

We demonstrate, by explicit construction, that a single band tight binding Hamiltonian defined on a class of deterministic fractals of the b = 3N Sierpinski type can give rise to an infinity of dispersionless, flat-band like states which…

Disordered Systems and Neural Networks · Physics 2015-03-11 Atanu Nandy , Biplab Pal , Arunava Chakrabarti

Electronic flat bands serve as a unique platform to achieve strongly-correlated phases. The emergence of a flat band around the Fermi level in 1T-TaS$_2$ in accompany with the development of a $\sqrt{13}\times\sqrt{13}$ charge density wave…

Materials Science · Physics 2022-01-13 Li Cheng , Xuanyu Long , Xiaobin Chen , Xiaolong Zou , Zheng Liu

Dispersionless flat bands can be classified into two types: (1) non-singular flat bands whose eigenmodes are completely characterized by compact localized states; and (2) singular flat bands that have a discontinuity in their Bloch…

Applied Physics · Physics 2023-08-01 Pragalv Karki , Jayson Paulose

The conditions leading to flat dispersionless frequency bands in truly one-dimensional parity-time ($\cal PT$) symmetric metamaterials comprising split-ring resonators (SRRs) arranged in a binary pattern are obtained analytically. In this…

Optics · Physics 2020-05-13 N. Lazarides , G. P. Tsironis

We propose and investigate a novel two-dimensional (2D) tight-binding model defined on a diamond-dodecagon lattice geometry that hosts multiple flat bands (FBs) and supports topological phase transitions driven by a magnetic flux. This…

Strongly Correlated Electrons · Physics 2026-02-16 Joydeep Majhi , Biplab Pal

In this work, we study the entanglement and topological properties of an extended flat-band Creutz ladder by considering a compacted localized state (CLS). Based on the CLS picture, we find a multiple flat-band extension from the…

Quantum Gases · Physics 2020-05-20 Yoshihito Kuno

Lieb lattice is one of the simplest bipartite lattices where compact localized states (CLS) are observed. This type of localisation is induced by the peculiar topology of the unit cell, where the modes are localized only on one sublattice…

Mesoscale and Nanoscale Physics · Physics 2023-09-13 Grzegorz Centała , Jarosław W. Kłos

\textit{Holey Graphene} (HG) is a widely used graphene material for the synthesis of high-purity and highly crystalline materials. In this work, we explore the electronic properties of a periodic distribution of lattice holes, demonstrating…

Mesoscale and Nanoscale Physics · Physics 2024-04-09 Abdiel de Jesús Espinosa-Champo , Gerardo G. Naumis

Flat bands imply lack of itinerancy due to some constraints that, in principle, results in anomalous behaviors with randomness. By a molecular orbital (MO) representation of the flat band systems, random MO models are introduced where the…

Disordered Systems and Neural Networks · Physics 2022-01-05 Yasuhiro Hatsugai

We demonstrate that a complete class of flat-band lattices with underlying commutative local symmetries exhibit a locally fragmented Hilbert space. The equitable partition theorem ensures distinct parities for the compact localized states…

Statistical Mechanics · Physics 2025-04-11 Eloi Nicolau , Anselmo M. Marques , Ricardo G. Dias , Verònica Ahufinger

1$T$-TaS$_2$ is the only insulating transition-metal dichalcogenide (TMD) with an odd number of electrons per unit cell. This insulating state is non-magnetic, making it a potential spin-liquid candidate. The unusual electronic behavior…

Strongly Correlated Electrons · Physics 2024-06-28 Amir Dalal , Jonathan Ruhman , Jörn W. F. Venderbos

Complex band structure generalizes conventional band structure by also considering wavevectors with complex components. In this way, complex band structure describes both the bulk-propagating states from conventional band structure and the…

Materials Science · Physics 2017-07-20 Matthew G. Reuter

We show that topological frequency band structures emerge in two-dimensional electromagnetic lattices of metamaterial components without the application of an external magnetic field. The topological nature of the band structure manifests…

Strongly Correlated Electrons · Physics 2015-06-05 Vassilios Yannopapas

According to the Onsager's semiclassical quantization rule, the Landau levels of a band are bounded by its upper and lower band edges at zero magnetic field. However, there are two notable systems where the Landau level spectra violate this…

Mesoscale and Nanoscale Physics · Physics 2021-11-17 Yoonseok Hwang , Jun-Won Rhim , Bohm-Jung Yang

We propose a new class of tight-binding models where a flat band is either gapped from or crossing right through a dispersive band on two-band (i.e., two sites/unit cell) tetragonal and honeycomb lattices. By imposing a condition on the…

Materials Science · Physics 2017-10-27 Tatsuhiro Misumi , Hideo Aoki

We derive symmetry-based conditions for tight-binding Hamiltonians with flatbands to have compact localized eigenstates occupying a single unit cell. The conditions are based on unitary operators commuting with the Hamiltonian and…

Mesoscale and Nanoscale Physics · Physics 2024-11-26 Jung-Wan Ryu , Alexei Andreanov , Hee Chul Park , Jae-Ho Han

We demonstrate experimentally the existence of compact localized states (CLSs) in a quasi-one-dimensional photonic rhombic lattice in presence of two distinct refractive-index gradients (i.e., a driven lattice ribbon) acting as external…

The realization of robust quantum storage devices relies on the ability to generate long-lived, spatially localized quantum states. In this work, we introduce a method for the targeted creation of compact excitations in flat-band lattices.…

Optics · Physics 2026-02-12 Carlo Danieli , Jie Liu , Rudolf A. Römer , Rodrigo A. Vicencio

We report the appearance of multiple numbers of completely flat band states in an extended Lieb lattice model in two dimensions with five atomic sites per unit cell. We also show that this edge-centered square lattice can host intriguing…

Strongly Correlated Electrons · Physics 2020-01-07 Ankita Bhattacharya , Biplab Pal

In flat-band systems with quenched kinetic energy, most of the conventional length scales related to the band dispersion become ineffectual. Although a few geometric length scales, such as the quantum metric length, can still be defined,…

Mesoscale and Nanoscale Physics · Physics 2025-12-01 Seokju Lee , Seung Hun Lee , Bohm-Jung Yang