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A: Fachverband Atomphysik
A 33: Poster VI
A 33.16: Poster
Donnerstag, 14. März 2024, 17:00–19:00, Tent A
Pairing dome from an emergent Feshbach resonance in a strongly repulsive bilayer model — •Hannah Lange1,2,3, Lukas Homeier1,3, Eugene Demler4, Ulrich Schollwöck1,3, Annabelle Bohrdt3,5, and Fabian Grusdt1,3 — 1LMU Munich, Germany — 2MPI for Quantum Optics, Garching, Germany — 3Munich Center for Quantum Science and Technology, Germany — 4ETH Zurich, Switzerland — 5University of Regensburg, Germany
A key to understanding unconventional superconductivity lies in unraveling the pairing mechanism of mobile charge carriers in doped antiferromagnets, giving rise to an effective attraction between charges even in the presence of strong repulsive Coulomb interactions. In this talk, I will consider a mixed-dimensional t-J ladder, a system that has recently been realized with ultracold atoms [1], and show how it can be extended with a nearest neighbor Coulomb repulsion. With repulsion turned off, the system features tightly bound hole pairs and large binding energies (closed channel). When the repulsion strength is increased, a crossover to more spatially extended, correlated pairs of individual holes (open channel) can be observed. In the latter regime, we still find robust binding energies that are strongly enhanced in the finite doping regime. The effective model in the strongly repulsive regime reveals that the attraction is mediated by the closed channel, in analogy to atomic Feshbach resonances between open and closed channels [2].
[1] Hirthe et al., Nature 2023
[2] Lange et al., arXiv:2309.15843, 2309.13040
Keywords: ultracold atoms; quantum magnetism; Feshbach resonances; BEC to BCS crossover; mixed-dimensional models