Regensburg 2025 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 43: Correlated Electrons: Other Theoretical Topics
TT 43.6: Vortrag
Donnerstag, 20. März 2025, 10:45–11:00, H33
Interplay of local and non-local electronic correlations in the Hubbard model — •Maria Chatzieleftheriou1, Silke Biermann2, and Evgeny Stepanov2 — 1Goethe University Frankfurt, Germany — 2Ecole Polytechnique, IP Paris, France
Strongly correlated electronic systems exhibit intriguing properties and highly complex phase diagrams, including metal-to-insulator transitions, magnetic/charge orderings and the field's holy grail: high temperature superconductivity. Their theoretical description is very challenging and various many-body methods have been developed to this direction. I will present results using state-of-the-art numerical techniques that allow for an accurate description of both strong local electronic correlations and spatial fluctuations. I will discuss the application of this approach on the study of the Hubbard model, relevant for a series of materials, where we have analyzed the interplay of Mott physics and magnetic fluctuations at half-filling. We have identified the Slater and Heisenberg regimes in the phase diagram, which are separated by a crossover region of competing spatial and local electronic correlations. This bridging of the two limits (the spin-fluctuation dominated Slater regime at weak coupling and the Mott insulator at strong-coupling) had been a key missing ingredient to our understanding of metal-insulator transitions in real materials. Lastly, I will present recently obtained results on the evolution of the system's magnetic and charge susceptibility as a function of doping.
Keywords: strongly correlated systems; Hubbard model; magnetic fluctuations; charge fluctuations; Mott transition