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Pseudogap in a Fermi-Hubbard quantum simulator
Lev Haldar Kendrick1, Anant Kale2, Youqi Gang2,3
1Department of Physics, Harvard University, Cambridge, MA, USA. lkendrick@g.harvard.edu.
Nature
|August 5, 2026
Summary
Researchers observed a pseudogap metal in the Hubbard model using quantum simulation. This finding advances understanding of doped Mott insulators and their connection to high-temperature superconductivity in quantum materials.
Area of Science:
- Condensed matter physics
- Quantum simulation
- Correlated electron systems
Background:
- Doped Mott insulators are crucial for understanding phenomena like cuprate superconductivity.
- The Hubbard model is a key theoretical framework for these complex quantum materials.
- Anomalous metallic states at low temperatures and intermediate doping remain poorly understood.
Purpose of the Study:
- To experimentally investigate the crossover between normal and pseudogapped metallic states in the Hubbard model.
- To characterize the pseudogap metal using thermodynamic and spectroscopic measurements.
- To explore the phase diagram of the Hubbard model concerning interactions and doping.
Main Methods:
- Utilized a cold-atom quantum simulator with reduced temperatures.
- Performed thermodynamic measurements (compressibility) to identify anomalies.
- Conducted spectroscopic measurements (lattice modulation spectra) to detect the pseudogap.
Main Results:
- Observed a crossover from a normal metal to a pseudogapped metal.
- Identified a line of thermodynamic anomalies in the phase diagram.
- Characterized the pseudogap, particularly in antinodal regions, indicating a loss of low-energy response.
Conclusions:
- Experimentally established and characterized the pseudogap metal in the Hubbard model.
- The findings suggest potential connections to charge order phenomena.
- Demonstrated the power of quantum simulation for tackling fundamental problems in correlated electron physics.
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