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Related papers: Double flat bands in kagome twisted bilayers

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Destructive interference between electron wavefunctions on the two-dimensional (2D) kagome lattice induces an electronic flat band, which could host a variety of interesting many-body quantum states. Key to realize these proposals is to…

Mesoscale and Nanoscale Physics · Physics 2024-09-12 Caiyun Chen , Jiangchang Zheng , Ruopeng Yu , Soumya Sankar , Hoi Chun Po , Kam Tuen Law , Berthold Jäck

In twisted bilayer graphene (TBG), a twist-angle-dependent competition between interlayer stacking energy and intralayer elastic energy results in flat rigid layers at large twist angles and lattice reconstruction at small twist angles.…

Mesoscale and Nanoscale Physics · Physics 2023-03-29 Xiao-Feng Zhou , Yi-Wen Liu , Chen-Yue Hao , Chao Yan , Qi Zheng , Ya-Ning Ren , Ya-Xin Zhao , Kenji Watanabe , Takashi Taniguchi , Lin He

Evidence of flat-band magnetism and half-metallicity in compressed twisted bilayer graphene is provided with first-principles calculations. We show that dynamic band-structure engineering in twisted bilayer graphene is possible by…

Materials Science · Physics 2019-06-05 Alejandro Lopez-Bezanilla

Special arrangements of atoms with more than one atom per unit cell, including honeycomb or kagome (woven bamboo mat) lattices, can host propagating excitations with non-trivial topology as defined by their evolution along closed paths in…

We investigate the electronic density redistribution of rotated bilayer graphene under a perpendicular electric field, showing that the layers are actually coupled even for large angles. This layer-layer coupling is evidenced by the charge…

Mesoscale and Nanoscale Physics · Physics 2012-03-26 E. Suárez Morell , P. Vargas , L. Chico , L. Brey

The kagome lattice has garnered significant attention due to its ability to host quantum spin Fermi liquid states. Recently, the combination of unique lattice geometry, electron-electron correlations, and adjustable magnetism in solid…

Strongly Correlated Electrons · Physics 2025-01-06 Man Li , Huan Ma , Rui Lou , Shancai Wang

We analyze the electronic structure of twisted bilayer graphene (TBG) nanoribbons close to the magic angle. We describe a transition from an incomplete to a complete moir\'e structure. By considering zigzag and armchair edge terminations,…

Mesoscale and Nanoscale Physics · Physics 2023-09-14 Elias Andrade , Pierre A. Pantaleón , Francisco Guinea , Gerardo G. Naumis

The existence of Bloch flat bands provides an facile pathway to realize strongly correlated phenomena in materials. Using density-functional theory and tight-binding approach, we show that the flat bands can form in twisted bilayer of…

Materials Science · Physics 2020-03-04 Xing-Ju Zhao , Yang Yang , Dong-Bo Zhang , Su-Huai Wei

Low-energy moir\'e flat bands in magic-angle twisted bilayer graphene (tBG) have demonstrated incredible potentials to exhibit rich exotic quantum phenomena. Theoretically, the moir\'e flat bands of tBG are based on the extended structures,…

Mesoscale and Nanoscale Physics · Physics 2022-05-23 Long-Jing Yin , Ling-Hui Tong , Yue-Ying Zhou , Yang Zhang , Yuan Tian , Li Zhang , Lijie Zhang , Zhihui Qin

The long wavelength moir\'e superlattices in twisted 2D structures have emerged as a highly tunable platform for strongly correlated electron physics. We study the moir\'e bands in twisted transition metal dichalcogenide homobilayers,…

Mesoscale and Nanoscale Physics · Physics 2021-11-19 Trithep Devakul , Valentin Crépel , Yang Zhang , Liang Fu

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

Moir\'e superlattices in the twisted bilayer graphene provide an unprecedented platform to investigate a wide range of exotic quantum phenomena. Recently, the twist degree of freedom has been introduced into various classical wave systems,…

Mesoscale and Nanoscale Physics · Physics 2021-12-01 Weixuan Zhang , Deyuan Zou , Qingsong Pei , Wenjing He , Houjun Sun , Xiangdong Zhang

We address the problem of flat band engineering in different prototypes of quasi-one dimensional kagome network through a generalized analytical proposition worked out within the tight-binding formalism. Exact fabrication of single particle…

Mesoscale and Nanoscale Physics · Physics 2024-11-05 Atanu Nandy

The interplay of hopping parameters that can give rise to flat bands in consequence of quantum interference in electronic, photonic, and other interesting materials has become an extensively studied topic. Most of the recognized structures…

Materials Science · Physics 2019-08-02 Chi-Cheng Lee , Antoine Fleurence , Yukiko Yamada-Takamura , Taisuke Ozaki

We investigate the electronic structure of alternating-twist triple Bernal-stacked bilayer graphene (t3BG) as a function of interlayer coupling $\omega$, twist angle $\theta$, interlayer potential difference $\Delta$, and top-bottom…

Mesoscale and Nanoscale Physics · Physics 2022-06-22 Jiseon Shin , Bheema Lingam Chittari , Yunsu Jang , Hongki Min , Jeil Jung

We evaluate the electronic transmission and conductance in bilayer graphene through a finite number of potential barriers. Further, we evaluate the dispersion relation in a bilayer graphene superlattice with a periodic potential applied to…

Mesoscale and Nanoscale Physics · Physics 2011-01-21 M. Barbier , P. Vasilopoulos , F. M. Peeters , J. Milton Pereira

The excitonic insulator (EI) state is a strongly correlated many-body ground state, arising from an instability in the band structure towards exciton formation. We show that the flat valence and conduction bands of a semiconducting diatomic…

Materials Science · Physics 2021-05-19 Gurjyot Sethi , Yinong Zhou , Linghan Zhu , Li Yang , Feng Liu

We propose that we can realize "tight-binding photonic bands" in metallophotonic waveguide networks, where the photonic bound states localized around the crossings of a network form a tight-binding band. The formation of bound states at the…

Materials Science · Physics 2012-12-18 Shimpei Endo , Takashi Oka , Hideo Aoki

'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

We demonstrate a photonic analog of twisted bilayer graphene that has ultra-flat photonic bands and exhibits extreme slow light behavior. Our twisted bilayer photonic device, which has an operating wavelength in C-band of the telecom…

Optics · Physics 2021-03-26 Haoning Tang , Fan Du , Stephen Carr , Clayton DeVault , Olivia Mello , Eric Mazur