Publications
Note: My collaboration with Dr. Hsin Lin ended in 2023. Some previously completed work may still appear in future publications.
Letters
Published in Physical Review B, 2025
The work proposes a new lattice model hosting low-energy states with a high pseudospin structure originating from its lattice geometry. This special electronic structure leads to enhanced band topology and quantum geometry in its twisted bilayer at magic angles. We further propose potential realizations in various 2D materials.
Recommended citation: Yi-Chun Hung*, Xiaoting Zhou*, and Arun Bansil. Geometry-driven moiré in twisted bilayers of high pseudospin fermions. Phys. Rev. B 112, L041403 (2025)
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Published in Physical Review Letters (Editors' Suggestion), 2024
The work study the electronic structure of twisted bilayer bipartite lattices with geometry-induced flat bands. We discovered that the flat bands persist and their numbers vary with the twist angle due to the bipartite lattice structure.
Recommended citation: Xiaoting Zhou*, Yi-Chun Hung*, Baokai Wang*, and Arun Bansil. Generation of isolated flat bands with tunable numbers through moiré engineering. Phys. Rev. Lett. 133, 236401 (2024).
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Regular Articles
Published in Physical Review B, 2025
The work propose a setup to realize the competing superconductivity and spin-density wave on the side surface of a superlattice made by stacking double quantum spin Hall insulators, along with potential material realizations and material specific analysis.
Recommended citation: Yi-Chun Hung, Chen-Hsuan Hsu, and Arun Bansil. Tunable Competing Electronic Orders in Double Quantum Spin Hall Superlattices. Phys. Rev. B 112, 195127 (2025).
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Published in Physical Review B, 2025
The work proposes an alternative approach of using double quantum spin Hall insutors to realize Majorana Kramers pair as domain wall states between two newly discovered strongly correlated phases in cold-atom systems.
Recommended citation: Yi-Chun Hung, Chen-Hsuan Hsu, and Arun Bansil. Majorana Kramers pairs in synthetic high-spin Chern insulators. Phys. Rev. B 111, 245145 (2025).
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Published in Physical Review B, 2025
The work study the relation between the band topology in the projective spectrum and the orbital Hall effects in group IV materials. We demonstrate the bulk-boundary correspondence in such a topological orbital Hall effect for the first time.
Recommended citation: Baokai Wang*, Yi-Chun Hung*, Hsin Lin, Sheng Li, Rui-Hua He, and Arun Bansil. Topological characteristics and bulk-boundary correspondence in the orbital Hall effect. Phys. Rev. B 111, 195102 (2025).
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Published in Physical Review B, 2024
The work provides a rigorous field-theoretical background to the higher-order topological insulator phase discovered in double quantum spin Hall insulators driven by anisotropic spin-(1) symmetry breaking perturbations.
Recommended citation: Yi-Chun Hung, Baokai Wang, Chen-Hsuan Hsu, Arun Bansil, and Hsin Lin. Time-reversal soliton pairs in even spin Chern number higher-order topological insulators. Phys. Rev. B 110, 035125 (2024).
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Published in Physical Review B, 2023
The work examines tight-binding models to demonstrate that anisotropic spin-U(1) symmetry breaking perturbations may give rise to the higher-order topological phases in quantum spin Hall insulators.
Recommended citation: Baokai Wang, Yi-Chun Hung, Xiaoting Zhou, Arun Bansil, and Hsin Lin. Higher-order topological phases hidden in quantum spin Hall insulators. Phys. Rev. B 108, 245103 (2023).
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Preprints
Published in arXiv, 2026
The work studies the moiré effect to the quantum geometry of the low-energy states in a twisted bilayer of kagome lattice with loop-current order. We discover that the quantum geometry of the twisted bilayer is qualitatively changed from the one of the monolayer due to the large inter-layer tunneling. Together with Floquet engineering, our results provides a path way to qualitatively engineer quantum geometry in twisted bilayer structure.
Recommended citation: Yi-Chun Hung, Xiaoting Zhou, and Arun Bansil. Twist-Induced Quantum Geometry Reconfiguration in Moiré Flat Bands arXiv:2603.20849.
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Published in arXiv, 2026
The work studies the electronic structure of a twisted heterobilayer: dice lattice on graphene with a twist. We discover that both the number of isolated zero-energy flat bands and their Berry curvature that concentrated at the $K, K^\prime$ valleys are tunable by the twist angle.
Recommended citation: Xiaoting Zhou*, Yi-Chun Hung*, and Arun Bansil. Quantum Geometry of Moiré Flat Bands Beyond the Valley Paradigm arXiv:2603.20852.
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Published in arXiv, 2026
The work demonstrate that, in topological material whose phase-protecting symmetry is broken, the quantum weight with a symmetry-breaking correction term are still lower bounded by the topological invariants. Such topological invariants are defined via the projected spectrum of quantum numbers of interest, such as spin. The proposed lower bound can be experimentally verified via optical probes under external fields.
Recommended citation: Yi-Chun Hung*, Yugo Onishi*, Hsin Lin, Liang Fu, and Arun Bansil. Extending Topological bound on Quantum Weight Beyond Symmetry-Protected Topological Phase. arXiv:2603.13041.
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Published in arXiv, 2026
The work proves a tripartite equivalence between the entanglement, the feature (i.e., the projected spectrum), and the Wilson loop spectra. This indicates that feature-energy complementarity, gapless boundary spectra appear either in the energy or the feature spectrum even when topological-phase-protecting symmetries are broken, is a more fundamental form of bulk boundary correspondence than gapless edge states.
Recommended citation: Yi-Chun Hung*, Tzen ong*, and Hsin Lin. Nested Feature Spectrum Topology: Tripartite Topological Equivalence of Feature, Entanglement, and Wilson Loop Spectrum arXiv:2603.13128.
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Published in arXiv, 2023
The work propose a framework to characterize the topological phases and the corresponding bulk-boundary correspondence through projective spectrum, which serve as a potential solution for symmetry breaking systems. The proof of bulk-boudary correspondence is provided in a later revision to be published.
Recommended citation: Baokai Wang*, Yi-Chun Hung*, Xiaoting Zhou, Tzen Ong, and Hsin Lin. Feature Spectrm Topology. arXiv:2310.14832.
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