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We present a simple scheme for implementing a one-dimensional (1D) magnetic-flux lattice of ultracold fermionic spin-$1/2$ atoms. The resulting tight-binding model supports gapped and gapless topological phases, and chiral currents for…

Quantum Gases · Physics 2017-11-02 Y. Deng , R. Lü , L. You

Flat bands can be divided into singular and non-singular ones according to the behavior of their Bloch wave function around band-crossing points in momentum space. We analyze the flat band in the Dice model, which can be tuned by a uniaxial…

Mesoscale and Nanoscale Physics · Physics 2024-04-11 Alexander Filusch , Holger Fehske

Two-dimensional moir\'e materials offer a powerful, twist-tunable platform for engineering electronic bands and correlations, though most studies to date have focused on small twist angles where flat bands arise from symmetry-pinned…

Mesoscale and Nanoscale Physics · Physics 2025-12-15 Giovanny Espitia , Seung Hun Lee , Calvin Kaiyu Chiu , Junyeong Ahn , Mit H. Naik

We show that the topologically protected flat band emerging on a surface of a nodal fermionic system promotes the surface superconductivity due to an infinitely large density of states associated with the flat band. The critical temperature…

Superconductivity · Physics 2015-05-27 N. B. Kopnin , T. T. Heikkilä , G. E. Volovik

Flat band systems have recently attracted significant attention due to their instability under small perturbations, which can lead to the stabilization of many exotic quantum phases. We study a trimer ladder which shows a middle flat band…

Strongly Correlated Electrons · Physics 2025-03-26 Sourabh Saha , Hosho Katsura , Manoranjan Kumar

'Magic'-angle twisted bilayer graphene has received a lot of interest due to its flat bands with potentially non-trivial topology that lead to intricate correlated phases. A spectrum with flat bands, however, does not require a twist…

Mesoscale and Nanoscale Physics · Physics 2021-07-07 Anastasiia Skurativska , Stepan S. Tsirkin , Fabian D Natterer , Titus Neupert , Mark H Fischer

Flat bands - single-particle energy bands - in tight-binding networks have attracted attention due to the presence of macroscopic degeneracies and their extreme sensitivity to perturbations. This makes them natural candidates for emerging…

Optics · Physics 2024-03-27 Carlo Danieli , Alexei Andreanov , Daniel Leykam , Sergej Flach

Recent chain-like structured materials have shown a robust superconducting phase. These materials exhibit the presence of quasi-one-dimensional bands (q1D) coupled to conventional higher-dimensional bands. On the mean-field level such…

Superconductivity · Physics 2021-02-11 T. T. Saraiva , A. A. Shanenko , A. Vagov , A. S. Vasenko

A flattened electronic band is one of several possible routes for increasing the strength of the pairing interactions in a superconductor. With this in mind, we show here that thermodynamic measurements of the high-Tc cuprates reveal an…

Strongly Correlated Electrons · Physics 2023-03-24 Neil Harrison , Mun K. Chan

Topological insulators and their intriguing edge states can be understood in a single-particle picture and can as such be exhaustively classified. Interactions significantly complicate this picture and can lead to entirely new insulating…

Strongly Correlated Electrons · Physics 2013-09-10 Emil J. Bergholtz , Zhao Liu

The properties of a phase at finite interactions can be significantly influenced by the underlying dispersion of the non-interacting Hamiltonian. We demonstrate this by studying the repulsive Hubbard model on the $2$D Lieb lattice, which…

Strongly Correlated Electrons · Physics 2017-12-27 Pramod Kumar , Tuomas I. Vanhala , Päivi Törmä

The Dirac bands and flat bands are difficult to coexist because they represent two extreme ends of electronic properties. However, in this paper, we propose a carbon-Kagome-lattice (CKL) family based on first-principles calculations, and…

Materials Science · Physics 2016-01-07 Chengyong Zhong , Yuee Xie , Yuanping Chen , Shengbai Zhang

Dispersionless (flat) electronic bands are investigated regarding their conductance properties. Due to "caging" of carriers these bands are usually insulating at partial filling, at least on the non-interacting level. Considering the…

Strongly Correlated Electrons · Physics 2015-01-14 Wolfgang Häusler

We use ultrafast optical spectroscopy to investigate the electronic and lattice dynamics of the charge-density wave (CDW) material 1$T$-TiSe$_2$ across various temperatures and pump fluences. We reveal a close relationship between the…

Strongly Correlated Electrons · Physics 2026-04-28 Xue-Qing Ye , Hao Liu , Qi-Yi Wu , Chen Zhang , Xiao-Fang Tang , Bo Chen , Chuan-Cun Shu , Hai-Yun Liu , Yu-Xia Duan , Peter M. Oppeneer , Jian-Qiao Meng

Graphene, made of sp2 hybridized carbon, is characterized with a Dirac band, representative of its underlying 2D hexagonal lattice. Fundamental understanding of graphene has recently spurred a surge of searching for 2D topological quantum…

Materials Science · Physics 2015-06-23 Miao Zhou , Zheng Liu , Wenmei Ming , Zhengfei Wang , Feng Liu

Kagome lattice has been actively studied for the possible realization of frustration-induced two-dimensional flat bands and a number of correlation-induced phases. Currently, the search for kagome systems with a nearly dispersionless flat…

Strongly Correlated Electrons · Physics 2024-06-27 Subhasis Samanta , Hwiwoo Park , Chanhyeon Lee , Sungmin Jeon , Hengbo Cui , Yong-Xin Yao , Jungseek Hwang , Kwang-Yong Choi , Heung-Sik Kim

We conclude our investigations on the QCD cross-over transition temperatures with 2+1 staggered flavours and one-link stout improvement. We extend our previous two studies [Phys. Lett. B643 (2006) 46, JHEP 0906:088 (2009)] by choosing even…

High Energy Physics - Lattice · Physics 2010-11-19 Szabolcs Borsanyi , Zoltan Fodor , Christian Hoelbling , Sandor D. Katz , Stefan Krieg , Claudia Ratti , Kalman K. Szabo

We report the theoretical discovery of a large class of 2D tight-binding models containing nearly-flat bands with nonzero Chern numbers. In contrast with previous studies, where nonlocal hoppings are usually required, the Hamiltonians of…

Strongly Correlated Electrons · Physics 2011-06-07 Kai Sun , Zheng-Cheng Gu , Hosho Katsura , S. Das Sarma

We study the influence of the band structure on the symmetry and superconducting transition temperature in the (solvable) weak-coupling limit of the repulsive Hubbard model. Among other results we find: 1) As a function of increasing…

Superconductivity · Physics 2015-11-11 Weejee Cho , Ronny Thomale , Srinivas Raghu , Steven A. Kivelson

We study superconductivity in the Hubbard model on various quasi-one-dimensional lattices with coexisting wide and narrow bands originating from multiple sites within a unit cell, where each site corresponds to a single orbital. The systems…

Superconductivity · Physics 2018-01-24 Karin Matsumoto , Daisuke Ogura , Kazuhiko Kuroki