Doping two-dimensional Fermi-Hubbard systems from polaronic metal to Fermi liquid
ORAL
Abstract
The Fermi-Hubbard model is believed to capture the essential ingredients of phenomena like high-Tc superconductivity, yet a complete understanding of its phases emerging upon doping remains elusive. Using our Fermi gas microscope with full spin and density resolution, we investigate the influence of different doping levels in a two-dimensional antiferromagnetic Hubbard system at temperatures around the superexchange energy. We observe the crossover from an anomalous metal to a conventional Fermi liquid. In order to obtain a better understanding of the nature of charge carriers within this crossover, we study the transformation of multi-point correlations between spins and holes. Starting from a magnetic polaron regime, we find the system evolves into a Fermi liquid featuring incommensurate magnetic fluctuations and fundamentally altered correlations. The crossover is completed for hole dopings around 30%. We benchmark theoretical approaches and discuss possible connections to lower temperature phenomena.
*We are supported by the Max Planck Society (MPG), the European Union (FET-Flag 817482, PASQUANS), the Max Planck Harvard Research Center for Quantum Optics (MPHQ) and Germany's Excellence Strategy –EXC-2111 – 390814868.
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Publication: J.Koepsell et al., arXiv:2009.04440 (2020)
Presenters
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Sarah Hirthe
- Max Planck Institute of Quantum Optics