Individual lithium atoms imaged in a spin-imbalanced Fermi gas trapped in an optical lattice

In a paper just published in the journal of Science, experimentalists at Princeton, led by Prof. Waseem Bakr, and several theorists including Prof. Ehsan Khatami of SJSU, report their direct observation of an exotic magnetic phase of matter with ultracold atoms that could help explain how high-temperature superconductivity — the complete loss of resistance to electric flow— works. By applying a strong magnetic field researchers find that atoms form a checkerboard pattern in the alignment of their intrinsic magnetic fields while slightly leaning away from each other, a state termed “canted antiferromagnetism”. Prof. Khatami used a state-of-the-art numerical technique to obtain numerical results for comparison to the experimental measurements based on a well-known theoretical model, which was crucial in guiding the experiments and allowing the team to characterize the new phase of atoms. The study is an important step towards better understanding electronic properties of solids, which can help us design better materials with specific properties we can harness in technology, energy and industry applications.