In Situ Probing of Correlations and Dynamics with Quantum Gases in Optical Lattices

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In this project, Dr. Chin's group at the University of Chicago identifies and investigates generic behaviors of strongly interacting atoms at ultralow temperatures. Once these generic correlations are determined, our understanding of a whole class of other complex quantum systems in nature will be greatly improved. One prominent goal is to understand high-Tc superconductivity, where the essential microscopic interactions can potentially be captured by fermionic atoms in optical lattices. Another fascinating goal is to explore the conjectured correspondence between the dynamics of atoms near a "quantum phase transition" and the quantum gravity in the early universe described by string theory.Overall, the project will identify emerging universal behaviors of quantum systems in the strong coupling regime. More specifically, temporal and spatial density correlations at all length scales are being investigated based on in situ imaging of Lithium-Cesium quantum gases with high spatial resolution. Spatial correlations can be extracted from same-time density measurement, while temporal correlations are being measured by locally poking the sample and monitoring the consequent density response. Among other directions, the group investigates pairing and superfluidity of fermions in lattices described by the Fermi-Hubbard model, and quantum critical transport, and its connection to the conjectured gauge-gravity duality.Correlations of particles are of fundamental interest in the research of condensed matter physics and materials science, since they lie at the heart of novel quantum phenomena, such as high-Tc superconductivity and quantum magnetism. Both pose a major challenge to our understanding of quantum materials. In recent years, quantum simulations based on ultracold atoms has emerged as a powerful tool and a fast growing research direction for unveiling the mystery of complex quantum phenomena.Finally, the group is initiating a new outreach program for K-12 students of public schools in the historical Chicago south side. This program offers a variety of science education activities to enhance the exposure of young students to the development of modern science and technology.