SKM 2023 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 65: Correlated Electrons: Other Theoretical Topics

TT 65.8: Vortrag

Freitag, 31. März 2023, 11:30–11:45, HSZ 204

Long-term memory magnetic correlations driven by local electronic repulsion — •Emin Moghadas¹, Matthias Reitner¹, Clemens Watzenböck¹, Giorgio Sangiovanni², and Alessandro Toschi¹ — ¹TU Wien — ²University of Würzburg

We investigate the onset of non-decaying temporal magnetic correlations in simple electronic models with on-site (Hubbard) electrostatic repulsion U. This effect[1] corresponds to the existence of a finite difference between the static/isothermal and the zero-frequency limit of the dynamical Kubo (magnetic) susceptibility. The long-term behavior is studied, on the one hand, analytically for the non-interacting Bethe lattice case in infinite dimensions and, on the other hand, for finite-size Hubbard ring-molecules by means of exact diagonalization. This way, we can directly observe and investigate the link between the emergence of infinitely long-lived temporal correlations and the degeneracies of the exact many-body eigenspectrum, possibly inferring underlying relations with the entropic properties of the system. Our findings also pave the way to study the enhancement of the static/isothermal density response in the proximity of metal-insulator transitions [2] and, in particular, of its possible impact on the renormalization of electron-phonon coupling.
[1] C. Watzenböck et al., Sci. Post Phys. (2022)
[2] M. Reitner et al., PRL (2020) and references therein.