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Register a new userMany-body Resonance in a Correlated Topological Kagome Antiferromagnet
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Songtian Sonia Zhang
Publication date
2020
fields
Physics
and research's language is
English
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We use scanning tunneling microscopy/spectroscopy (STM/S) to elucidate the atomically resolved electronic structure in strongly correlated topological kagome magnet Mn$_3$Sn. In stark contrast to its broad single-particle electronic structure, we observe a pronounced resonance with a Fano line shape at the Fermi level resembling the many-body Kondo resonance. We find that this resonance does not arise from the step edges or atomic impurities, but the intrinsic kagome lattice. Moreover, the resonance is robust against the perturbation of a vector magnetic field, but broadens substantially with increasing temperature, signaling strongly interacting physics. We show that this resonance can be understood as the result of geometrical frustration and strong correlation based on the kagome lattice Hubbard model. Our results point to the emergent many-body resonance behavior in a topological kagome magnet.
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We utilize a general strategy to turn classes of frustration free lattice models into similar classes containing quantum many-body scars within the bulk of their spectrum while preserving much or all of the original symmetry. We apply this strategy to a well-known class of quantum dimer models on the kagome lattice with a large parameter space. We discuss that the properties of the resulting scar state(s), including entanglement entropy, are analytically accessible. Settling on a particular representative within this class of models retaining full translational symmetry, we present numerical exact diagonalization studies on lattices of up to 60 sites, giving evidence that non-scar states conform to the eigenstate thermalization hypothesis. We demonstrate that bulk energies surrounding the scar are distributed according to the Gaussian ensemble expected of their respective symmetry sector. We further contrast entanglement properties of the scar state with that of all other eigenstates.
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