Ring states around impurities act as a spectroscopic probe for delicate topological insulators in a phononic metamaterial and persist after multicellularity is removed by a weakly hybridizing orbital.
Ring states in topological materials
6 Pith papers cite this work. Polarity classification is still indexing.
6
Pith papers citing it
abstract
Ingap states are commonly observed in semiconductors and are often well characterized by a hydrogenic model within the effective mass approximation. However, when impurities are strong, they significantly perturb all momentum eigenstates, leading to deep-level bound states that reveal the global properties of the unperturbed band structure. In this work, we discover that the topology of band wavefunctions can impose zeros in the impurity-projected Green's function within topological gaps. These zeros can be interpreted as spectral attractors, defining the energy at which ingap states are pinned in the presence of infinitely strong local impurities. Their pinning energy is found by minimizing the level repulsion of band eigenstates onto the ingap state. We refer to these states as ring states, marked by a mixed band character and a node at the impurity site, guaranteeing their orthogonality to the bare impurity eigenstates and a weak energy dependence on the impurity strength. We show that the inability to construct symmetric and exponentially localized Wannier functions ensures topological protection of ring states. Linking ring states together, the edge or surface modes can be recovered for any topologically protected phase. Therefore, ring states can also be viewed as building blocks of boundary modes, offering a framework to understand bulk-boundary correspondence.
representative citing papers
Step edges in 3D topological metals carry a robust non-integer conductance K e²/h determined by the bulk.
Hybridized topological zero modes cause ac conductivity to scale as log ω at the critical delocalization point in the disordered SSH chain due to stretched-exponential wavefunction decay.
Sign-problem-free QMC simulations show that strong impurities reduce the critical interaction for superconductivity in a BHZ-Hubbard model by nucleating Cooper pairs in impurity-induced subgap ring states.
Minimal model of topological random binary alloy shows dopant-centric chiral current loops enabling topological phase transitions in trivial hosts and metallic phases with inter-domain edge modes in opposite-chirality cases.
A semi-holographic model couples a fermion to a holographic composite sector, yielding poles-zeros duality in the Green's function that distinguishes metallic and Mott-insulating phases through choice of quantization.
citing papers explorer
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Observation of ring states in a delicate topological insulator
Ring states around impurities act as a spectroscopic probe for delicate topological insulators in a phononic metamaterial and persist after multicellularity is removed by a weakly hybridizing orbital.
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Step-Edge Anomaly in Topological Metals
Step edges in 3D topological metals carry a robust non-integer conductance K e²/h determined by the bulk.
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Quantum Critical Dynamics Induced by Topological Zero Modes
Hybridized topological zero modes cause ac conductivity to scale as log ω at the critical delocalization point in the disordered SSH chain due to stretched-exponential wavefunction decay.
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Emergent superconductivity upon disordering a topological insulator
Sign-problem-free QMC simulations show that strong impurities reduce the critical interaction for superconductivity in a BHZ-Hubbard model by nucleating Cooper pairs in impurity-induced subgap ring states.
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Topological random alloy
Minimal model of topological random binary alloy shows dopant-centric chiral current loops enabling topological phase transitions in trivial hosts and metallic phases with inter-domain edge modes in opposite-chirality cases.
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Poles-zeros duality in semi-holographic Mott insulators
A semi-holographic model couples a fermion to a holographic composite sector, yielding poles-zeros duality in the Green's function that distinguishes metallic and Mott-insulating phases through choice of quantization.