Nearly flatbands with nontrivial topology.
By K. Sun, Z. Gu, Hosho Katsura, S. Das Sarma. Physical Review Letters, 2010
600 citations recorded by the source corpus.
We report the theoretical discovery of a class of 2D tight-binding models containing nearly flatbands with nonzero Chern numbers. In contrast with previous studies, where nonlocal hoppings are usually required, the Hamiltonians of our models only require short-range hopping and have the potential to be realized in cold atomic gases. Because of the similarity with 2D continuum Landau levels, these topologically nontrivial nearly flatbands may lead to the realization of fractional anomalous quantum Hall states and fractional topological insulators in real materials. Among the models we discover, the most interesting and practical one is a square-lattice three-band model which has only nearest-neighbor hopping. To understand better the physics underlying the topological flatband aspects, we also present the studies of a minimal two-band model on the checkerboard lattice.
Subfields: Atomic and Molecular Physics, and Optics, Materials Chemistry
View Paper: https://www.semanticscholar.org/paper/3d146cf8e15b1b8a505e268ba588140bfd124cff
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Citations in the corpus
- Artificial flat band systems: from lattice models to experiments (2018, background): “[82] Kai Sun, Zhengcheng Gu, Hosho Katsura, and S.”
- Spontaneous fractional Chern insulators in transition metal dichalcogenide moiré superlattices (2021, background): “[45] Kai Sun, Zhengcheng Gu, Hosho Katsura, and S.”
- Fractional quantum Hall physics in topological flat bands (2013, unknown): “The recent flurry of interest in the FQHE in topological flat bands began with the work of three groups [13,14,15]; several authors have since constructed models with nearly flat (non-dispersing) Chern bands which allow interactions to dominate at partial fillings while leaving the gap to neighborin”
- Flat bands, strange metals and the Kondo effect (2023, unknown): “For multi-orbital systems such as the iron pnictides or chalcogenides, the Mott transition can become orbitally selective, allowing metallic behaviour to survive at the largest values of U / W .”
- Band geometry, Berry curvature and superfluid weight (2016, background): “A quasiflat band with nonzero Chern number may support various fractional quantum Hall states [9–15], and it has been shown that flat bands can enhance the superconducting transition temperature because of the high density of states [16–19].”