Tunable Flat Band in Large‐Scale Kagome Lattice of Single Layer (BETS) 2 GaCl 4

2019 ◽  
Vol 256 (12) ◽  
pp. 1900346
Author(s):  
Abdou Hassanien
2021 ◽  
Vol 126 (19) ◽  
Author(s):  
Gurjyot Sethi ◽  
Yinong Zhou ◽  
Linghan Zhu ◽  
Li Yang ◽  
Feng Liu

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Seunghyun Park ◽  
Soonmin Kang ◽  
Haeri Kim ◽  
Ki Hoon Lee ◽  
Pilkwang Kim ◽  
...  

AbstractWith the advanced investigations into low-dimensional systems, it has become essential to find materials having interesting lattices that can be exfoliated down to monolayer. One particular important structure is a kagome lattice with its potentially diverse and vibrant physics. We report a van-der-Waals kagome lattice material, Pd3P2S8, with several unique properties such as an intriguing flat band. The flat band is shown to arise from a possible compact-localized state of all five 4d orbitals of Pd. The diamagnetic susceptibility is precisely measured to support the calculated susceptibility obtained from the band structure. We further demonstrate that Pd3P2S8 can be exfoliated down to monolayer, which ultimately will allow the possible control of the localized states in this two-dimensional kagome lattice using the electric field gating.


Author(s):  
Liqiang Zhuo ◽  
Huiru He ◽  
Ruimin Huang ◽  
Zhi Li ◽  
Weibin Qiu ◽  
...  

2020 ◽  
Vol 125 (13) ◽  
Author(s):  
Tsz-Him Leung ◽  
Malte N. Schwarz ◽  
Shao-Wen Chang ◽  
Charles D. Brown ◽  
Govind Unnikrishnan ◽  
...  

2018 ◽  
Vol 4 (11) ◽  
pp. eaau4511 ◽  
Author(s):  
Zhi Li ◽  
Jincheng Zhuang ◽  
Li Wang ◽  
Haifeng Feng ◽  
Qian Gao ◽  
...  

The energy dispersion of fermions or bosons vanishes in momentum space if destructive quantum interference occurs in a frustrated Kagome lattice with only nearest-neighbor hopping. A discrete flat band (FB) without any dispersion is consequently formed, promising the emergence of fractional quantum Hall states at high temperatures. Here, we report the experimental realization of an FB with possible nontrivial topology in an electronic Kagome lattice on twisted multilayer silicene. Because of the unique low-buckled two-dimensional structure of silicene, a robust electronic Kagome lattice has been successfully induced by moiré patterns after twisting the silicene multilayers. The electrons are localized in the Kagome lattice because of quantum destructive interference, and thus, their kinetic energy is quenched, which gives rise to an FB peak in the density of states. A robust and pronounced one-dimensional edge state has been revealed at the Kagome edge, which resides at higher energy than the FB. Our observations of the FB and the exotic edge state in electronic Kagome lattice open up the possibility that fractional Chern insulators could be realized in two-dimensional materials.


2020 ◽  
Author(s):  
Man Li ◽  
Qi Wang ◽  
Guangwei Wang ◽  
Zhihong Yuan ◽  
Wenhua Song ◽  
...  

Abstract Kagome-lattice of 3d-transition metals hosting Weyl/Dirac fermions and topological flat bands exhibit non-trivial topological characters and novel quantum phases, such as anomalous Hall effect and fractional quantum Hall effect. With consideration of spin-orbit coupling and electron correlation, several instabilities could be induced. The complete characters of the electronic structure of kagome lattice, i.e. the saddle point, Dirac-cone, and flat band, around the Fermi energy (EF) remain elusive in magnetic kagome materials. We present the first experimental observation of the complete features in ferromagnetic kagome layers of YMn6Sn6 helically coupled along the c-axis, by using angle-resolved photoemission spectroscopy and band structure calculations. We demonstrate a Dirac dispersion near EF arising from a spin-polarized orbital, which carries an intrinsic Berry curvature and contributes to the anomalous Hall effect in transport measurements. In addition, a flat band and a saddle point with a high density of states and with orbital-selective characters near EF are observed. These multi-orbital kagome features could cause multi-orbital magnetism. The Dirac fermion, flat band and saddle point in the vicinity of EF open an opportunity in manipulating the topological properties in magnetic materials.


2020 ◽  
Vol 9 (6) ◽  
Author(s):  
Saeed Jahromi ◽  
Roman Orus ◽  
Didier Poilblanc ◽  
Frédéric Mila

We study the zero-temperature phase diagram of the spin-1/2 Heisenberg model with breathing anisotropy (i.e., with different coupling strength on the upward and downward triangles) on the kagome lattice. Our study relies on large scale tensor network simulations based on infinite projected entangled-pair state and infinite projected entangled-simplex state methods adapted to the kagome lattice. Our energy analysis suggests that the U(1) algebraic quantum spin-liquid (QSL) ground-state of the isotropic Heisenberg model is stable up to very large breathing anisotropy until it breaks down to a critical lattice-nematic phase that breaks rotational symmetry in real space through a first-order quantum phase transition. Our results also provide further insight into the recent experiment on vanadium oxyfluoride compounds which has been shown to be relevant platforms for realizing QSL in the presence of breathing anisotropy.


2013 ◽  
Vol 87 (6) ◽  
Author(s):  
Rodrigo A. Vicencio ◽  
Magnus Johansson

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