{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/122107"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/122107","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Designing stoichiometric Eu3+ materials for dense, optically addressable quantum memory","abstract":"Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2025-12-01","abstract_html":"Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2025-12-01","abstract_has_math":false,"creators":["Riedel, Zachary W."],"institution":"University of Illinois at Urbana-Champaign","degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Materials Science & Engr","degree_department":null,"school":null,"contributors":["Shoemaker, Daniel P","Goldschmidt, Elizabeth A","Schleife, André","Shim, Moonsub"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2023,"date_issued":"2023-12","date_published":"2023-12","updated_at":"2026-07-22T22:25:00Z","subjects":["Quantum Memory","Lanthanides","Rare-earths","Crystal Growth","Materials Design","Photoluminescence","Diffraction","Density Functional Theory"],"languages":["en","eng"],"rights":["Copyright 2023 Zachary W. Riedel"],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://hdl.handle.net/2142/122107","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Shoemaker, Daniel P","Goldschmidt, Elizabeth A","Schleife, André","Shim, Moonsub"]},{"key":"dc:creator","label":"Author","values":["Riedel, Zachary W."]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2023-12","2023-11-16"]},{"key":"dc:type","label":"Dc Type","values":["text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Materials Science & Engr"]},{"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":["Quantum Memory","Lanthanides","Rare-earths","Crystal Growth","Materials Design","Photoluminescence","Diffraction","Density Functional Theory"]}]},{"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 2023 Zachary W. Riedel"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://hdl.handle.net/2142/122107"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2025-12-01","The student, Zachary Riedel, accepted the attached license on 2023-11-10 at 10:34.","The student, Zachary Riedel, submitted this Dissertation for approval on 2023-11-10 at 10:37.","This Dissertation was approved for publication on 2023-11-16 at 10:16.","DSpace SAF Submission Ingestion Package generated from Vireo submission #19901 on 2024-03-01 at 13:29:35","Rare-earth elements are well suited for building long-lived quantum memory. Their filled 5s and 5p orbitals shield their 4f-4f orbital optical transitions from external influences, leading to long, millisecond-scale optical transition coherence times. Here, we diverge from typical rare-earth doping approaches by using stoichiometric rare-earth compounds for quantum memory systems. Instead of containing low concentrations of randomly dispersed rare-earth cations, stoichiometric systems drastically increase the rare-earth density while improving homogeneity by reducing local strain and point defects. Improved homogeneity then narrows the inhomogeneous linewidth of the optical transitions. For a stoichiometric Eu3+ compound with an ultra-narrow inhomogeneous linewidth, we can resolve optically addressable transitions between nuclear spin states, which have up to hours-long coherence times. But the only compound reported to have the necessary linewidth, Eu35Cl3·6H2O, has practical limitations. To search for new candidates, I began by looking for known Eu3+ compounds with large distances between Eu3+ cations in the crystal lattice. I grew single crystals of the metal-organic frameworks Eu(HCOO)3·(HCONH2)2 and Eu(HCOO)3 from heated solutions. Both have optical lifetimes >1.4 ms at 1.4 K, but only Eu(HCOO)3 is stable in air. I then improved the Eu(HCOO)3 synthesis procedure, producing transparent, well-faceted crystals at room temperature. The second system from my initial search was the layered oxide EuAl3(BO3)4. Growing EuAl3(BO3)4 crystals from two flux systems, I showed that coherent polymorph domains shift the Eu3+ site symmetry within a single crystal. I also used a flux growth procedure to isolate the material’s C2/c polymorph and helped develop a new procedure for synthesizing polycrystalline EuAl3(BO3)4 in a conventional microwave. To limit linewidth broadening from isotopes, I next proposed unrealized stoichiometric Eu3+ candidates containing mononuclidic ions and used DFT to predict their stability, navigating the computational challenges posed by 4f electrons. I then synthesized the new, DFT-predicted double perovskite Cs2NaEuF6. From my DFT calculations and a search of the Materials Project database, I identified phosphates and iodates as the next chemical spaces to search for narrow linewidth compounds. I synthesized crystals of two iodates, NaEu(IO3)4 and Eu(IO3)3, both of which have a high intensity 5D0→7F0 transition at room temperature. My synthesized candidates span a variety of chemical spaces and are platforms for studying the influence of structural motifs and defect chemistry on the inhomogeneous linewidth, providing a pathway to discovering ultra-narrow linewidth compounds."]},{"key":"dc:format","label":"Dc Format","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Designing stoichiometric Eu3+ materials for dense, optically addressable quantum memory"]}]}],"canonical_facts":{"dc:contributor":["Shoemaker, Daniel P","Goldschmidt, Elizabeth A","Schleife, André","Shim, Moonsub"],"dc:creator":["Riedel, Zachary W."],"dc:date":["2023-12","2023-11-16"],"dc:description":["Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2025-12-01","The student, Zachary Riedel, accepted the attached license on 2023-11-10 at 10:34.","The student, Zachary Riedel, submitted this Dissertation for approval on 2023-11-10 at 10:37.","This Dissertation was approved for publication on 2023-11-16 at 10:16.","DSpace SAF Submission Ingestion Package generated from Vireo submission #19901 on 2024-03-01 at 13:29:35","Rare-earth elements are well suited for building long-lived quantum memory. Their filled 5s and 5p orbitals shield their 4f-4f orbital optical transitions from external influences, leading to long, millisecond-scale optical transition coherence times. Here, we diverge from typical rare-earth doping approaches by using stoichiometric rare-earth compounds for quantum memory systems. Instead of containing low concentrations of randomly dispersed rare-earth cations, stoichiometric systems drastically increase the rare-earth density while improving homogeneity by reducing local strain and point defects. Improved homogeneity then narrows the inhomogeneous linewidth of the optical transitions. For a stoichiometric Eu3+ compound with an ultra-narrow inhomogeneous linewidth, we can resolve optically addressable transitions between nuclear spin states, which have up to hours-long coherence times. But the only compound reported to have the necessary linewidth, Eu35Cl3·6H2O, has practical limitations. To search for new candidates, I began by looking for known Eu3+ compounds with large distances between Eu3+ cations in the crystal lattice. I grew single crystals of the metal-organic frameworks Eu(HCOO)3·(HCONH2)2 and Eu(HCOO)3 from heated solutions. Both have optical lifetimes >1.4 ms at 1.4 K, but only Eu(HCOO)3 is stable in air. I then improved the Eu(HCOO)3 synthesis procedure, producing transparent, well-faceted crystals at room temperature. The second system from my initial search was the layered oxide EuAl3(BO3)4. Growing EuAl3(BO3)4 crystals from two flux systems, I showed that coherent polymorph domains shift the Eu3+ site symmetry within a single crystal. I also used a flux growth procedure to isolate the material’s C2/c polymorph and helped develop a new procedure for synthesizing polycrystalline EuAl3(BO3)4 in a conventional microwave. To limit linewidth broadening from isotopes, I next proposed unrealized stoichiometric Eu3+ candidates containing mononuclidic ions and used DFT to predict their stability, navigating the computational challenges posed by 4f electrons. I then synthesized the new, DFT-predicted double perovskite Cs2NaEuF6. From my DFT calculations and a search of the Materials Project database, I identified phosphates and iodates as the next chemical spaces to search for narrow linewidth compounds. I synthesized crystals of two iodates, NaEu(IO3)4 and Eu(IO3)3, both of which have a high intensity 5D0→7F0 transition at room temperature. My synthesized candidates span a variety of chemical spaces and are platforms for studying the influence of structural motifs and defect chemistry on the inhomogeneous linewidth, providing a pathway to discovering ultra-narrow linewidth compounds."],"dc:format":["application/pdf"],"dc:identifier":["https://hdl.handle.net/2142/122107"],"dc:language":["en","eng"],"dc:rights":["Copyright 2023 Zachary W. Riedel"],"dc:subject":["Quantum Memory","Lanthanides","Rare-earths","Crystal Growth","Materials Design","Photoluminescence","Diffraction","Density Functional Theory"],"dc:title":["Designing stoichiometric Eu3+ materials for dense, optically addressable quantum memory"],"dc:type":["text"],"thesis:degree_discipline":["Materials Science & Engr"],"thesis:degree_level":["Dissertation"],"thesis:degree_name":["Ph.D."],"thesis:institution_name":["University of Illinois at Urbana-Champaign"]},"updated_at":"2026-07-22T22:25:00Z"}