TITLE: Interaction Effects in Topologically Non-Trivial Many-Body Systems
AUTHOR: Dr. Jyoti Bisht, Quantum Systems Unit OIST, Japan
WHEN: October 5 2026. 12:00
WHERE: Sala de reuniones 608, ICMM-CSIC
INVITED BY: Xi Chen
ABSTRACT: The effect of Hubbard interaction, U, on the edge states in the half-filled Su-Schrieffer-Heeger (SSH) and Rice-Mele (RM) chain of electrons is investigated by studying the behaviour of charge quasiparticles using Kumar representation [1] and density matrix renormalization group (DMRG) method. For any finite dimerization of hopping, by increasing the interaction, the edge states are found to transmigrate from the physical charge gap to a high energy gap and also presenting an uncommon case where repulsion leads to zero-energy edge states in RM chain [2,3]. Next we investigate the Arbitrary Finite Kronig-Penney (AFKP) model, which is a continuum system, to explore the robustness of topological features against local disorder [4,5]. Motivated by these insights, we finally investigate the effect of spatial modulation on the spectral function within the AFKP. In the presence of quasi periodicity, the extended states get localized as the modulation amplitude increases.
1. B. Kumar, Phys. Rev. B 77, 205115 (2008).
2. J. Bisht, S. Jalal, B. Kumar, Phys. Rev. B 110, 245110 (2024).
3. J. Bisht, B. Kumar, arXiv:2508.21008.
4. S. S. Nair, G. Žlabys, W.-B. He, T. Fogarty and T. Busch, Phys. Rev. A 111, 033313 (2025).
5. W.-B. He, G. Zlabys, H. Hiyane, S. S. Nair and T. Busch, Phys. Rev. A 111, 013312 (2025).
