Flat bands on a spherical surface from Landau levels to giant-quantum-number orbitals

Abstract Flat bands result in a divergent density of states and high sensitivity to interactions in physical systems. While such bands are well known in systems under magnetic fields, their realization and behavior in zero-field settings remain largely unexplored. Here we compare the behavior of ele...

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Bibliographic Details
Main Authors: Chen-Xin Jiang, Zi-Xiang Hu, Bo Yang
Format: Article
Language:English
Published: Nature Portfolio 2025-07-01
Series:Communications Physics
Online Access:https://doi.org/10.1038/s42005-025-02208-9
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Summary:Abstract Flat bands result in a divergent density of states and high sensitivity to interactions in physical systems. While such bands are well known in systems under magnetic fields, their realization and behavior in zero-field settings remain largely unexplored. Here we compare the behavior of electrons confined to a single flat band on the surface of a sphere to those in flat bands under a magnetic field. The zero-field flat band exhibits an additional C(2) symmetry, which causes electrons to symmetrically cluster on opposite sides of the sphere’s center when a trapping potential is introduced, resulting in a unique form of long-range “entanglement”. To explore these findings experimentally, we propose a feasible setup to explore the unique properties of zero-field flat bands on spherical substrates, offering a promising route for studying interaction-driven states in spherical geometry without external fields.
ISSN:2399-3650