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Zwierlein, Martin W. Patel, Parth Massachusetts Institute of Technology. Department of Physics 2023-05-15T19:33:05Z 2023-05-15T19:33:05Z 2022-05 2023-05-10T22:35:39.481Z https://hdl.handle.net/1721.1/150695 Transport of strongly interacting fermions is crucial for systems as varied as high-𝑇 subscript 𝑐 superconductors, twisted bi-layer graphene, nuclear fission, and neutron stars. In this thesis, I will describe the experiments we performed to measure the transport properties of a strongly-interacting atomic Fermi gas. This system features interactions as strong as allowed by quantum mechanics and features one of the highest pairing strength, with a superfluid transition temperature on the order of the Fermi temperature. Moreover, it is also scale-invariant, making its properties directly relevant for systems with many order of magnitude higher densities. We trap these atoms in a uniform box potential made from repulsive laser light, the key experimental advancement that makes the transport experiment presented here possible. Here, we observe a very low, universal, Heisenberg-uncertainty limited diffusion of both sound and heat by studying the propagation of sound waves and conduction of heat in a uniform gas. Similar to a growing number of high-𝑇 subscript 𝑐 superconductors, we observe anomalous transport properties, like the viscosity and thermal conductivity, that cannot be explained by a Fermi-liquid theory. We show the temperature dependence of all non-zero transport properties, which constitutes a complete characterization of transport phenomena in the spin-balanced, strongly-interacting Fermi gas. Our findings inform theories of fermion transport, with relevance for hydrodynamic flow of electrons, neutrons, and quarks. Ph.D. Massachusetts Institute of Technology In Copyright - Educational Use Permitted Copyright MIT http://rightsstatements.org/page/InC-EDU/1.0/ Quantum transport in strongly interacting, ultracold fermi gases in box potentials Thesis application/pdf Doctoral Doctor of Philosophy Publication unknown unknown <Publication xmlns="https://www.openaire.eu/cerif-profile/1.1/" id="3db53e59-1fc5-49af-b8f0-06b6dc2ecc3e"> <Type xmlns="https://www.openaire.eu/cerif-profile/vocab/COAR_Publication_Types">http://purl.org/coar/resource_type/c_1843</Type> <Title>Quantum transport in strongly interacting, ultracold fermi gases in box potentials</Title> <PublishedIn> <Publication> </Publication> </PublishedIn> <PublicationDate>2022-05</PublicationDate> <Authors> <Author> <DisplayName>Patel, Parth</DisplayName> <Affiliation> <OrgUnit> </OrgUnit> </Affiliation> </Author> </Authors> <Editors> </Editors> <Publishers> <Publisher> <DisplayName>Massachusetts Institute of Technology</DisplayName> <OrgUnit /> </Publisher> </Publishers> <License>http://rightsstatements.org/page/InC-EDU/1.0/</License> <Abstract>Transport of strongly interacting fermions is crucial for systems as varied as high-𝑇 subscript 𝑐 superconductors, twisted bi-layer graphene, nuclear fission, and neutron stars. In this thesis, I will describe the experiments we performed to measure the transport properties of a strongly-interacting atomic Fermi gas. This system features interactions as strong as allowed by quantum mechanics and features one of the highest pairing strength, with a superfluid transition temperature on the order of the Fermi temperature. Moreover, it is also scale-invariant, making its properties directly relevant for systems with many order of magnitude higher densities. We trap these atoms in a uniform box potential made from repulsive laser light, the key experimental advancement that makes the transport experiment presented here possible. Here, we observe a very low, universal, Heisenberg-uncertainty limited diffusion of both sound and heat by studying the propagation of sound waves and conduction of heat in a uniform gas. Similar to a growing number of high-𝑇 subscript 𝑐 superconductors, we observe anomalous transport properties, like the viscosity and thermal conductivity, that cannot be explained by a Fermi-liquid theory. We show the temperature dependence of all non-zero transport properties, which constitutes a complete characterization of transport phenomena in the spin-balanced, strongly-interacting Fermi gas. Our findings inform theories of fermion transport, with relevance for hydrodynamic flow of electrons, neutrons, and quarks.</Abstract> <Access xmlns="http://purl.org/coar/access_right" > </Access> </Publication>