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Antiferromagnetic Correlations in Two-Dimensional Fermionic Mott-Insulating and Metallic Phases.
J H Drewes1, L A Miller1,2, E Cocchi1,2
1Physikalisches Institut, University of Bonn, Wegelerstrasse 8, 53115 Bonn, Germany.
Physical Review Letters
|May 13, 2017
Summary
Researchers observed antiferromagnetic correlations in ultracold fermionic atoms within a 2D optical lattice as temperature decreased. These magnetic correlations rapidly vanished when the system was doped away from half filling.
Area of Science:
- Quantum physics
- Condensed matter physics
- Atomic physics
Background:
- Antiferromagnetic correlations are crucial in understanding magnetism.
- Ultracold fermionic atoms in optical lattices provide a controllable platform for studying quantum many-body phenomena.
- The two-dimensional Hubbard model is a key theoretical framework for strongly correlated electron systems.
Purpose of the Study:
- To experimentally investigate the emergence of antiferromagnetic correlations in ultracold fermionic atoms.
- To probe the behavior of the two-dimensional Hubbard model at low temperatures.
- To understand the impact of doping on magnetic correlations.
Main Methods:
- Utilizing ultracold fermionic atoms in a two-dimensional optical lattice.
- Performing simultaneous in-situ density measurements of both spin components.
- Decreasing temperature to observe changes in magnetic correlations.
Main Results:
- Observed the emergence of antiferromagnetic correlations with decreasing temperature at half filling.
- Data approached the Heisenberg model predictions for localized spins under strong interactions.
- Demonstrated a rapid decay of magnetic correlations upon doping away from half filling.
Conclusions:
- Experimental evidence for antiferromagnetic correlations in fermionic atoms at low temperatures.
- The system mimics localized spin behavior in the Heisenberg model at half filling.
- Magnetic correlations are sensitive to doping in this quantum simulation.
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