{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/88039"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/88039","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Transport and disorder-induced localization of ultracold Fermi gases","abstract":"We experimentally study localization and dynamics of ultracold fermions in speckle and optical lattice potentials to explore Anderson localization, many-body localization, and relaxation dynamics in strongly correlated systems. Anderson localization is probed by releasing non-interacting, spin-polarized gases into three dimensional, anisotropic disordered potentials produced from optical speckle. A fraction of the atoms are localized by the disorder, and a mobility edge is found separating localized from extended states. The length scale of the speckle is varied, and the localized state is found to scale linearly with the geometric mean of the speckle autocorrelation length. We realize the Fermi Hubbard model by loading atoms in a cubic optical lattice. Non-equilibrium momentum distributions are created via Raman transitions, and the excitation relaxation rate is measured in the lattice. Transport experiments were performed in a disordered optical lattice to explore the disordered Hubbard model. These experiments reveal localization in the presence of strong interactions and an interaction driven metal-to-insulator transition. The localized state is found to be insensitive to a doubling in the temperature of the gas and is consistent with predictions of many-body localization.","abstract_html":"We experimentally study localization and dynamics of ultracold fermions in speckle and optical lattice potentials to explore Anderson localization, many-body localization, and relaxation dynamics in strongly correlated systems. Anderson localization is probed by releasing non-interacting, spin-polarized gases into three dimensional, anisotropic disordered potentials produced from optical speckle. A fraction of the atoms are localized by the disorder, and a mobility edge is found separating localized from extended states. The length scale of the speckle is varied, and the localized state is found to scale linearly with the geometric mean of the speckle autocorrelation length. We realize the Fermi Hubbard model by loading atoms in a cubic optical lattice. Non-equilibrium momentum distributions are created via Raman transitions, and the excitation relaxation rate is measured in the lattice. Transport experiments were performed in a disordered optical lattice to explore the disordered Hubbard model. These experiments reveal localization in the presence of strong interactions and an interaction driven metal-to-insulator transition. The localized state is found to be insensitive to a doubling in the temperature of the gas and is consistent with predictions of many-body localization.","abstract_has_math":false,"creators":["McGehee, William R"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Physics","degree_department":null,"school":null,"contributors":["DeMarco, Brian L.","Mason, Nadya","Gadway, Bryce","Clark, Bryan"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2015,"date_issued":"2015-09-29T20:38:25Z","date_published":"2015-09-29T20:38:25Z","updated_at":"2026-07-22T22:26:31Z","subjects":["Anderson Localization","Many-Body Localization","Optical Speckle","Optical Lattice","Ultracold Atoms","Disordered Transport","Strongly-Interacting Materials","Hubbard Model","Fermi-Hubbard Model","Fermi Gas"],"languages":["en"],"rights":["Copyright 2015 William Russell McGehee"],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/2142/88039","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["DeMarco, Brian L.","Mason, Nadya","Gadway, Bryce","Clark, Bryan"]},{"key":"dc:creator","label":"Author","values":["McGehee, William R"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2015-09-29T20:38:25Z","2015-08","2015-07-14","2015-8"]},{"key":"dc:type","label":"Dc Type","values":["text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Physics"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Dissertation"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Ph.D."]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["University of Illinois at Urbana-Champaign"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Anderson Localization","Many-Body Localization","Optical Speckle","Optical Lattice","Ultracold Atoms","Disordered Transport","Strongly-Interacting Materials","Hubbard Model","Fermi-Hubbard Model","Fermi Gas"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["Copyright 2015 William Russell McGehee"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["http://hdl.handle.net/2142/88039"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["We experimentally study localization and dynamics of ultracold fermions in speckle and optical lattice potentials to explore Anderson localization, many-body localization, and relaxation dynamics in strongly correlated systems. Anderson localization is probed by releasing non-interacting, spin-polarized gases into three dimensional, anisotropic disordered potentials produced from optical speckle. A fraction of the atoms are localized by the disorder, and a mobility edge is found separating localized from extended states. The length scale of the speckle is varied, and the localized state is found to scale linearly with the geometric mean of the speckle autocorrelation length. We realize the Fermi Hubbard model by loading atoms in a cubic optical lattice. Non-equilibrium momentum distributions are created via Raman transitions, and the excitation relaxation rate is measured in the lattice. Transport experiments were performed in a disordered optical lattice to explore the disordered Hubbard model. These experiments reveal localization in the presence of strong interactions and an interaction driven metal-to-insulator transition. The localized state is found to be insensitive to a doubling in the temperature of the gas and is consistent with predictions of many-body localization.","Submission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2015-09-29 without embargo terms","The student, William McGehee, accepted the attached license on 2015-07-13 at 21:28.","The student, William McGehee, submitted this Dissertation for approval on 2015-07-13 at 21:52.","This Dissertation was approved for publication on 2015-07-14 at 15:38.","DSpace SAF Submission Ingestion Package generated from Vireo submission #8448 on 2015-09-29 at 13:22:47","Made available in DSpace on 2015-09-29T20:38:25Z (GMT). No. of bitstreams: 2 MCGEHEE-DISSERTATION-2015.pdf: 10640550 bytes, checksum: 541bd0c3bcdfb10ee1cfb56d36e841bc (MD5) LICENSE.txt: 4212 bytes, checksum: 2227b62d028cd89d663bc3212b4f8840 (MD5) Previous issue date: 2015-07-14"]},{"key":"dc:format","label":"Dc Format","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Transport and disorder-induced localization of ultracold Fermi gases"]}]}],"canonical_facts":{"dc:contributor":["DeMarco, Brian L.","Mason, Nadya","Gadway, Bryce","Clark, Bryan"],"dc:creator":["McGehee, William R"],"dc:date":["2015-09-29T20:38:25Z","2015-08","2015-07-14","2015-8"],"dc:description":["We experimentally study localization and dynamics of ultracold fermions in speckle and optical lattice potentials to explore Anderson localization, many-body localization, and relaxation dynamics in strongly correlated systems. Anderson localization is probed by releasing non-interacting, spin-polarized gases into three dimensional, anisotropic disordered potentials produced from optical speckle. A fraction of the atoms are localized by the disorder, and a mobility edge is found separating localized from extended states. The length scale of the speckle is varied, and the localized state is found to scale linearly with the geometric mean of the speckle autocorrelation length. We realize the Fermi Hubbard model by loading atoms in a cubic optical lattice. Non-equilibrium momentum distributions are created via Raman transitions, and the excitation relaxation rate is measured in the lattice. Transport experiments were performed in a disordered optical lattice to explore the disordered Hubbard model. These experiments reveal localization in the presence of strong interactions and an interaction driven metal-to-insulator transition. The localized state is found to be insensitive to a doubling in the temperature of the gas and is consistent with predictions of many-body localization.","Submission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2015-09-29 without embargo terms","The student, William McGehee, accepted the attached license on 2015-07-13 at 21:28.","The student, William McGehee, submitted this Dissertation for approval on 2015-07-13 at 21:52.","This Dissertation was approved for publication on 2015-07-14 at 15:38.","DSpace SAF Submission Ingestion Package generated from Vireo submission #8448 on 2015-09-29 at 13:22:47","Made available in DSpace on 2015-09-29T20:38:25Z (GMT). No. of bitstreams: 2 MCGEHEE-DISSERTATION-2015.pdf: 10640550 bytes, checksum: 541bd0c3bcdfb10ee1cfb56d36e841bc (MD5) LICENSE.txt: 4212 bytes, checksum: 2227b62d028cd89d663bc3212b4f8840 (MD5) Previous issue date: 2015-07-14"],"dc:format":["application/pdf"],"dc:identifier":["http://hdl.handle.net/2142/88039"],"dc:language":["en"],"dc:rights":["Copyright 2015 William Russell McGehee"],"dc:subject":["Anderson Localization","Many-Body Localization","Optical Speckle","Optical Lattice","Ultracold Atoms","Disordered Transport","Strongly-Interacting Materials","Hubbard Model","Fermi-Hubbard Model","Fermi Gas"],"dc:title":["Transport and disorder-induced localization of ultracold Fermi gases"],"dc:type":["text"],"thesis:degree_discipline":["Physics"],"thesis:degree_level":["Dissertation"],"thesis:degree_name":["Ph.D."],"thesis:institution_name":["University of Illinois at Urbana-Champaign"]},"updated_at":"2026-07-22T22:26:31Z"}