A cold-atom Fermi–Hubbard antiferromagnet

By A. Mazurenko, C. Chiu, G. Ji, M. Parsons, M. Kanász-Nagy, R. Schmidt, F. Grusdt, E. Demler, D. Greif, M. Greiner. Nature, 2016

647 citations recorded by the source corpus.

Exotic phenomena in systems with strongly correlated electrons emerge from the interplay between spin and motional degrees of freedom. For example, doping an antiferromagnet is expected to give rise to pseudogap states and high-temperature superconductors. Quantum simulation using ultracold fermions in optical lattices could help to answer open questions about the doped Hubbard Hamiltonian, and has recently been advanced by quantum gas microscopy. Here we report the realization of an antiferromagnet in a repulsively interacting Fermi gas on a two-dimensional square lattice of about 80 sites at a temperature of 0.25 times the tunnelling energy. The antiferromagnetic long-range order manifests through the divergence of the correlation length, which reaches the size of the system, the development of a peak in the spin structure factor and a staggered magnetization that is close to the ground-state value. We hole-dope the system away from half-filling, towards a regime in which complex many-body states are expected, and find that strong magnetic correlations persist at the antiferromagnetic ordering vector up to dopings of about 15 per cent. In this regime, numerical simulations are challenging and so experiments provide a valuable benchmark. Our results demonstrate that microscopy of cold atoms in optical lattices can help us to understand the low-temperature Fermi–Hubbard model.

Subfields: Atomic and Molecular Physics, and Optics, Condensed Matter Physics

View Paper: https://www.semanticscholar.org/paper/f556e1187b0fd9a03ea7e6172969deffdd7af124

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Atomic and Molecular Physics, and Optics

In Condensed Matter Physics

Citations in the corpus

Probing many-body dynamics on a 51-atom quantum simulator (2017, background): “These systems are already addressing computationally difficult problems in quantum dynamics [11] and the fermionic Hubbard model [12].”
Quantum algorithms to simulate many-body physics of correlated fermions. (2017, methodology): “Recently, the antiferromagnet phase of the Fermi-Hubbard model was realized in optical lattices of about 80 sites at a temperature of 1/4 times the tunneling energy [29].”
Observing the Space- and Time-Dependent Growth of Correlations in Dynamically Tuned Synthetic Ising Models with Antiferromagnetic Interactions (2017, background): “, the observation of long-range antiferromagnetic order [17].”
Superconductivity, superfluidity and quantum geometry in twisted multilayer systems (2021, background): “While continuum ultracold gases routinely show superfluidity, bringing fermions in lattices to the superfluid temperatures is a challenge, although advances in realizing antiferromagnetic states [141] suggest it should be reached soon.”
Absence of Superconductivity in the Pure Two-Dimensional Hubbard Model (2019, background): “An intense experimental effort is on-going with ultracold atoms in optical lattices to realize “quantum simulations” of this model [59–62].”
Quantum simulation of the Hubbard model with ultracold fermions in optical lattices (2018, neutral): “Doping the system by controlling the density of the bulk, a recent experiment has observed the progressive suppression and eventually the cancellation of the long-range antiferromagnetic order [86].”