SAMOP 2023 – scientific programme
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Q: Fachverband Quantenoptik und Photonik
Q 50: Quantum Gases: Fermions I
Q 50.5: Talk
Thursday, March 9, 2023, 12:00–12:15, F342
Competing antiferromagnetic and superfluid phases in the Feshbach-Hubbard model — •Victor Bezerra1 and Axel Pelster2 — 1Friedrich-Engels-Gymnasium, Emmentalerstraße 67, 13407 Berlin, Germany — 2Physics Department and Research Center OPTIMAS, Rheinland-Pfälzische Technische Universität Kaiserslautern-Landau, Germany
Competing phases play an important role in strongly interacting systems, as for example in the case of superconductivity and antiferromagnetism. Alongside condensed matter-systems ultracold atoms loaded in optical lattices have shown to be quite promising to simulate and to understand the behavior of strongly correlated systems. In this work we study a two-dimensional model that contains both the usual repulsive Fermi-Hubbard Hamiltonian and a pairing term due Feshbach bosons, and study there the competition of antiferromagnetic order and conventional pairing order within a zero-temperature mean-field theory. With this we investigate, at first, the properties of the crossover from a Bose-Einstein condensate (BEC) phase to the Bardeen-Cooper-Schrieffer (BCS)-like phase, where a reentrant behavior occurs and band-insulator lobes are obtained analytically. Secondly, concerning the antiferromagnetic (AF) order, the well-known mean-field results are reproduced. And, finally, we obtain a quantum phase diagram, which reveals an intriguing interplay from a BEC-BCS crossover to an insulating AF order.