Fermionic many-body topology in cavity-coupled Su-Schrieffer-Heeger chains

Abstract:We study the effects of cavity-mediated interactions on the symmetries and topological properties of a Su-Schrieffer-Heeger chain coupled to a single mode photonic cavity. Considering an off-resonant regime we use the high-frequency expansion in order to obtain an effective fermionic Hamiltonian with cavity-mediated interactions. We characterize the effects of the cavity on topology in a finite size chain by studying three different fermionic many-body topological markers using exact diagonalization: correlation functions between edges in a chain with open boundary conditions, and a winding number based on the single-particle Green's function and bulk electric polarization via the many-body formula by Resta for a chain with periodic boundary conditions. Importantly, we show that chiral symmetry is not broken by the cavity in the many-body ground state in the high-frequency limit. Our work highlights the importance of the cavity-mediated many-body interactions in understanding the symmetry and topology of the system.

Mesoscale and Nanoscale Physics (cond-mat.mes-hall); Strongly Correlated Electrons (cond-mat.str-el); Quantum Physics (quant-ph)

arXiv:2604.13936 [cond-mat.mes-hall]

(or arXiv:2604.13936v2 [cond-mat.mes-hall] for this version)

https://doi.org/10.48550/arXiv.2604.13936 Focus to learn more arXiv-issued DOI via DataCite

Phys. Rev. B 114, 165423 (2026)

https://doi.org/10.1103/n492-rvhb Focus to learn more DOI(s) linking to related resources

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