Hulet, Randall G.2009-06-042009-06-042006Kamar, Ramsey I.. "Measurements of the interactions in a paired zero temperature lithium-6 gas throughout the BEC-BCS crossover." (2006) Master’s Thesis, Rice University. <a href="https://hdl.handle.net/1911/17887">https://hdl.handle.net/1911/17887</a>.https://hdl.handle.net/1911/17887Understanding the effects of interactions on the ground-state of a paired degenerate Fermi gas throughout the BEC-BCS crossover has been a long standing physical quest for which countless papers have been written. The crossover describes the smooth transition of the physics of a BEC of tightly bound dimers to that of a paired BCS superfluid. A Feshbach resonance is used to tune the interactions necessary to study the crossover. Right around resonance the interactions are expected to be parameterized by a single universal parameter beta [1--3]. This thesis describes a measurement of the axial size of paired, 6Li clouds in the BEC-BCS crossover and provides a comparison with theory. In the BEC regime, absolute measurements of the molecular scattering length are compared with the atomic scattering length and the ratio is compared with theory. Finally, a measurement of beta is made and compared with theory.45 p.application/pdfengCopyright is held by the author, unless otherwise indicated. Permission to reuse, publish, or reproduce the work beyond the bounds of fair use or other exemptions to copyright law must be obtained from the copyright holder.Molecular physicsAtomic physicsOpticsThesisTHESIS PHYS. 2006 KAMAR