{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/129926"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/129926","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Tunable cold-atom momentum space double wells for phase-sensitive measurements","abstract":"Submission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2025-10-20 without embargo terms","abstract_html":"Submission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2025-10-20 without embargo terms","abstract_has_math":false,"creators":["Williams, Garrett R."],"institution":"University of Illinois Urbana-Champaign","degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Physics","degree_department":null,"school":null,"contributors":["Gadway, Bryce","DeMarco, Brian","Cooper, Lance","Goldschmidt, Elizabeth"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2025,"date_issued":"2025-07-10","date_published":"2025-07-10","updated_at":"2026-07-22T22:25:06Z","subjects":["Lasers","Atoms","States","Nonlinearities","Quantum"],"languages":["en","eng"],"rights":["Copyright 2025 Garrett Williams"],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://hdl.handle.net/2142/129926","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Gadway, Bryce","DeMarco, Brian","Cooper, Lance","Goldschmidt, Elizabeth"]},{"key":"dc:creator","label":"Author","values":["Williams, Garrett R."]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2025-07-10","2025-08"]},{"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 Urbana-Champaign"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Lasers","Atoms","States","Nonlinearities","Quantum"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["en","eng"]},{"key":"dc:rights","label":"Dc Rights","values":["Copyright 2025 Garrett Williams"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://hdl.handle.net/2142/129926"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Submission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2025-10-20 without embargo terms","The student, Garrett Williams, accepted the attached license on 2025-07-09 at 12:00.","The student, Garrett Williams, submitted this Dissertation for approval on 2025-07-09 at 12:12.","This Dissertation was approved for publication on 2025-07-10 at 08:58.","DSpace SAF Submission Ingestion Package generated from Vireo submission #22459 on 2025-10-20 at 20:15:06","As quantum technologies move from theoretical development to practical realization, experimental access to quantum nonlinearities and critical phenomena becomes essential for advancing applications in quantum sensing, computing, and networking. These capabilities are underpinned by the fundamental behaviors of quantum matter near phase transitions and as well as the nonlinear interactions associated with them. This work explores the interplay between tunable quantum criticality and nonlinear interactions in ultracold atomic momentum-state double wells engineered using a rubidium-87 Bose-Einstein condensate (BEC). We discuss the development of our single-cell BEC apparatus and the various techniques necessary for its construction. We then use it to experimentally investigate Bragg-coupled atomic momentum modes and observe signatures consistent with beyond-the-mean-field effects in a system exhibiting features characteristic of collective quantum magnetism. These results point toward the presence of tunable nonlinearities in momentum space and offer a pathway for exploring momentum-state squeezing as a tool for enhanced quantum sensing. In parallel, this work also identifies a conceptual correspondence between the momentum-space “double-well” structure observed in our BEC system and phase transitions in a distinct class of quantum materials: quantum critical crystals at cryogenic temperatures. This cross-platform analogy highlights the potential universality of quantum critical phenomena and underscores the broader relevance of our findings. The studies described in this work demonstrate that the controlled exploration of phase transitions and nonlinearities in cold atom systems not only provides insight into fundamental quantum many-body physics but also supports the development of quantum-enhanced technologies. The ability to engineer and probe phase-sensitive effects in a highly tunable and coherent systems opens new avenues for implementing precision sensors, robust quantum communication protocols, and complex computational operations. Ultimately, the synergy between quantum criticality and phase sensitive measurements facilitated by induced nonlinearities may serve as a foundational principle for the next generation of quantum devices."]},{"key":"dc:format","label":"Dc Format","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Tunable cold-atom momentum space double wells for phase-sensitive measurements"]}]}],"canonical_facts":{"dc:contributor":["Gadway, Bryce","DeMarco, Brian","Cooper, Lance","Goldschmidt, Elizabeth"],"dc:creator":["Williams, Garrett R."],"dc:date":["2025-07-10","2025-08"],"dc:description":["Submission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2025-10-20 without embargo terms","The student, Garrett Williams, accepted the attached license on 2025-07-09 at 12:00.","The student, Garrett Williams, submitted this Dissertation for approval on 2025-07-09 at 12:12.","This Dissertation was approved for publication on 2025-07-10 at 08:58.","DSpace SAF Submission Ingestion Package generated from Vireo submission #22459 on 2025-10-20 at 20:15:06","As quantum technologies move from theoretical development to practical realization, experimental access to quantum nonlinearities and critical phenomena becomes essential for advancing applications in quantum sensing, computing, and networking. These capabilities are underpinned by the fundamental behaviors of quantum matter near phase transitions and as well as the nonlinear interactions associated with them. This work explores the interplay between tunable quantum criticality and nonlinear interactions in ultracold atomic momentum-state double wells engineered using a rubidium-87 Bose-Einstein condensate (BEC). We discuss the development of our single-cell BEC apparatus and the various techniques necessary for its construction. We then use it to experimentally investigate Bragg-coupled atomic momentum modes and observe signatures consistent with beyond-the-mean-field effects in a system exhibiting features characteristic of collective quantum magnetism. These results point toward the presence of tunable nonlinearities in momentum space and offer a pathway for exploring momentum-state squeezing as a tool for enhanced quantum sensing. In parallel, this work also identifies a conceptual correspondence between the momentum-space “double-well” structure observed in our BEC system and phase transitions in a distinct class of quantum materials: quantum critical crystals at cryogenic temperatures. This cross-platform analogy highlights the potential universality of quantum critical phenomena and underscores the broader relevance of our findings. The studies described in this work demonstrate that the controlled exploration of phase transitions and nonlinearities in cold atom systems not only provides insight into fundamental quantum many-body physics but also supports the development of quantum-enhanced technologies. The ability to engineer and probe phase-sensitive effects in a highly tunable and coherent systems opens new avenues for implementing precision sensors, robust quantum communication protocols, and complex computational operations. Ultimately, the synergy between quantum criticality and phase sensitive measurements facilitated by induced nonlinearities may serve as a foundational principle for the next generation of quantum devices."],"dc:format":["application/pdf"],"dc:identifier":["https://hdl.handle.net/2142/129926"],"dc:language":["en","eng"],"dc:rights":["Copyright 2025 Garrett Williams"],"dc:subject":["Lasers","Atoms","States","Nonlinearities","Quantum"],"dc:title":["Tunable cold-atom momentum space double wells for phase-sensitive measurements"],"dc:type":["text"],"thesis:degree_discipline":["Physics"],"thesis:degree_level":["Dissertation"],"thesis:degree_name":["Ph.D."],"thesis:institution_name":["University of Illinois Urbana-Champaign"]},"updated_at":"2026-07-22T22:25:06Z"}