Topology and Obstruction in Multi-level Systems
F. Nur Ünal (University of Cambridge & University of Birmingham)
Abstract: While the landscape of free-fermion topological phases has drastically been expanded in the last decades, recently novel multi-gap topological phases have been discovered with non-Abelian braiding properties of band singularities. In systems with C2T or PT symmetry, the ability of these band nodes to annihilate pairwise is path dependent, and the sign of their charges can be changed by braiding nodes in adjacent gaps. I will present non-Abelian frame charges associated with band nodes and discuss their observable signatures. I will talk about the effects of the non-Bravais lattice configuration and obstruction on the multi-gap topological Euler invariant, illustrate physical signatures of these non-trivial Brillouin zone boundary conditions.
PRL 133, 093404 (2024); Nat Comm 15, 1144 (2024); PRL 125, 053601 (2020); Alsaiari et al, to appear (2025)
condensed mattergeneral relativity and quantum cosmologyHEP - latticeHEP - theorymathematical physicsquantum physics
Audience: researchers in the topic
Quantum Theories of Fields, Matter, and Strings
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| Organizers: | Yunus Sargut*, Burak Oguz, Basar Deniz*, Arda Hasar, Cagdas Ulus Agca, Deniz Nazif Tastan, Omer Onder |
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