Quantum gas microscopy of an attractive Fermi-Hubbard system
Abstract
The attractive Fermi-Hubbard model is the simplest theoretical model for studying pairing and superconductivity of fermions on a lattice. Although its s-wave pairing symmetry excludes it as a microscopic model for high-temperature superconductivity, it exhibits much of the relevant phenomenology, including a short-coherence length at intermediate coupling and a pseudogap regime with anomalous properties. Here we study an experimental realization of this model using a two-dimensional (2D) atomic Fermi gas in an optical lattice. Our site-resolved measurements on the normal state reveal checkerboard charge-density-wave correlations close to half-filling. A "hidden" SU(2) pseudo-spin symmetry of the Hubbard model at half-filling guarantees superfluid correlations in our system, the first evidence for such correlations in a single-band Hubbard system of ultracold fermions. Compared to the paired atom fraction, we find the charge-density-wave correlations to be a much more sensitive thermometer, useful for optimizing cooling into superfluid phases in future experiments.
Keywords
Cite
@article{arxiv.1705.02039,
title = {Quantum gas microscopy of an attractive Fermi-Hubbard system},
author = {Debayan Mitra and Peter T. Brown and Elmer Guardado-Sanchez and Stanimir S. Kondov and Trithep Devakul and David A. Huse and Peter Schauss and Waseem S. Bakr},
journal= {arXiv preprint arXiv:1705.02039},
year = {2018}
}