A neutral-atom Hubbard quantum simulator in the cryogenic regime

Area of Science:

• Condensed-matter physics
• Quantum simulation
• Ultracold atomic gases

Background:

• Ultracold fermionic atoms in optical lattices are key for simulating Hubbard models, fundamental to condensed-matter physics.
• Current accessible temperatures in these systems are too high for many critical research questions.
• Simulating strongly correlated states classically is extremely challenging.

Purpose of the Study:

• To demonstrate a significant reduction in temperature for ultracold fermionic atoms in optical lattices.
• To enable large-scale quantum simulations of the Hubbard model in a new, lower-temperature regime.
• To explore new pathways for achieving low temperatures in doped Hubbard models.

Main Methods:

• Dynamic control of Hubbard model parameters to transform low-entropy states into strongly correlated states.
• Achieving ultra-low temperatures (T/t = 0.05) at half-filling, verified by comparison with numerically exact simulations.
• Utilizing quantum simulation to identify novel low-temperature pathways for doped systems, validated against auxiliary-field quantum Monte Carlo simulations.

Main Results:

• Achieved a several-fold reduction in temperature, reaching T/t = 0.05 at half-filling with near-saturated antiferromagnetic order.
• Identified a new quantum simulation pathway for achieving low temperatures in doped Hubbard models.
• Observed short-range spin correlations consistent with state-of-the-art numerical methods.

Conclusions:

• The demonstrated temperature reduction opens a new regime for quantum simulations of the Hubbard model.
• This advancement facilitates the study of complex phenomena like the pseudogap and stripe phases in material analogues.
• The work fosters synergy between quantum simulation, numerical methods, and theoretical studies, paving the way for new physics discoveries.