This thesis describes significant advances in experimental capabilities using ultracold polar molecules. While ultracold polar molecules are an idyllic platform for quantum chemistry and quantum many-body physics, molecular samples prior to this work failed to be quantum degenerate, were plagued by chemical reactions, and lacked any evidence of many-body physics. These limitations were overcome by loading molecules into an optical lattice to control and eliminate collisions and hence chemical reactions. This led to observations of many-body spin dynamics using rotational states as a pseudo-spin, and the realization of quantum magnetism with long-range interactions and strong many-body correlations.
Further, a 'quantum synthesis' technique based on atomic insulators allowed the author to increase the filling fraction of the molecules in the lattice to 30%, a substantial advance which corresponds to an entropy-per-molecule entering the quantum degenerate regime and surpasses the so-called percolations threshold where long-range spin propagation is expected.
Lastly, this work describes the design, construction, testing, and implementation of a novel apparatus for controlling polar molecules. It provides access to: high-resolution molecular detection and addressing; large, versatile static electric fields; and microwave-frequency electric fields for driving rotational transitions with arbitrary polarization. Further, the yield of molecules in this apparatus has been demonstrated to exceed 10^5, which is a substantial improvement beyond the prior apparatus, and an excellent starting condition for direct evaporative cooling to quantum degeneracy.
Covey
Enhanced Optical and Electric Manipulation of a Quantum Gas of KRb Molecules jetzt bestellen!
Weitere Infos & Material
Chapter1. Introduction.- Chapter2. Experimental Background and Overview.- Chapter 3. Quantum-State Controlled Chemical Reactions and Dipolar Collisions.- Chapter 4. Suppression of Chemical Reactions in a 3D Lattice.- Chapter 5. Quantum Magnetism with Polar Molecules in a 3D Optical Lattice.- Chapter 6. A Low Entropy Quantum Gas of Polar Molecules in a 3D Optical Lattice.- Chapter 7. The New Apparatus – Enhanced Optical and Electric Manipulation of Ultracold Polar Molecules.- Chapter 8. Designing, Building and Testing the New Apparatus.- Chapter 9. Experimental Procedure – Making Molecules in the New Apparatus.- Chapter 10. New Physics with the New Apparatus – High Resolution Optical Detection and Large, Stable Electric Fields.- Chapter 11. Outlook.
Jacob Covey received his PhD in 2017 for research undertaken at JILA, the University of Colorado, Boulder, and NIST. He holds a postdoctoral research position at Caltech.