{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/110401"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/110401","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"X-ray scattering studies of charge density waves in cuprate and pnictide superconductors","abstract":"This Dissertation was approved for publication on 2020-12-17 at 08:47.","abstract_html":"This Dissertation was approved for publication on 2020-12-17 at 08:47.","abstract_has_math":false,"creators":["Lee, Sangjun"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Physics","degree_department":null,"school":null,"contributors":["Abbamonte, Peter","Madhavan, Vidya","Fradkin, Eduardo","Filippini, Jeffrey"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2021,"date_issued":"2021-09-17T01:10:26Z","date_published":"2021-09-17T01:10:26Z","updated_at":"2026-07-22T22:24:50Z","subjects":["Superconductor","Unconventional superconductors","Charge density wave","X-ray scattering","Resonant soft x-ray scattering"],"languages":["en"],"rights":["Copyright 2021 Sangjun Lee"],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/2142/110401","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Abbamonte, Peter","Madhavan, Vidya","Fradkin, Eduardo","Filippini, Jeffrey"]},{"key":"dc:creator","label":"Author","values":["Lee, Sangjun"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2021-09-17T01:10:26Z","2020-12-17","2021-05"]},{"key":"dc:type","label":"Dc Type","values":["text","Thesis"]},{"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":["Superconductor","Unconventional superconductors","Charge density wave","X-ray scattering","Resonant soft x-ray scattering"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["Copyright 2021 Sangjun Lee"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["http://hdl.handle.net/2142/110401"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["This Dissertation was approved for publication on 2020-12-17 at 08:47.","DSpace SAF Submission Ingestion Package generated from Vireo submission #16127 on 2021-09-16 at 16:39:02","Made available in DSpace on 2021-09-17T01:10:26Z (GMT). No. of bitstreams: 3 LEE-DISSERTATION-2021.pdf: 18629262 bytes, checksum: 4d3b262167e16ead0650c065d63d74cb (MD5) LICENSE.txt: 4208 bytes, checksum: 2dd5a28b5395a037dedb0b3fa2f75158 (MD5) PROQUEST_LICENSE.txt: 4554 bytes, checksum: 4e7a4e4bdb388c4749df18263c8f136d (MD5) Previous issue date: 2020-12-17","The phase diagrams of unconventional superconductors exhibit many different broken-symmetry phases near superconductivity, such as antiferromagnetism, charge density wave, spin density wave, and nematic order. The proximity and similar temperature scales of these orders suggest superconductivity and other order parameters are intertwined, and how they intertwine is a longstanding problem in condensed matter physics. Among the phases found in the vicinity of superconductivity, charge density wave (CDW) has been found in nearly all cuprate superconductors and observed to have an intimate relationship with superconductivity. Thus, characterizing the nature of CDWs is crucial for understanding the mechanism of unconventional superconductivity. Here, we studied CDWs in cuprate and pnictide superconductors using various x-ray scattering techniques. We discovered new CDW phases in BaNi2As2 and Co-, Sr-doped systems, confirming a generic presence of CDW in the phase diagram of unconventional superconductors, and the nature of the superconductivity in these systems are closely related to the presence of CDW. We also precisely measured the temperature and doping evolution of the CDW wave vector in La1.8-xEu0.2SrxCuO4, revealing the effect of the finite charge compressibility and the coupling of charge and spin order on the wave vector change. Furthermore, energy- and time-resolved resonant soft x-ray scattering experiments on the CDW in La2-xBaxCuO4 were performed to reveal a previously unidentified fluctuating nature of the CDW.","Submission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2021-09-16 without embargo terms","The student, Sangjun Lee, accepted the attached license on 2020-12-15 at 21:07.","The student, Sangjun Lee, submitted this Dissertation for approval on 2020-12-15 at 21:20."]},{"key":"dc:format","label":"Dc Format","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["X-ray scattering studies of charge density waves in cuprate and pnictide superconductors"]}]}],"canonical_facts":{"dc:contributor":["Abbamonte, Peter","Madhavan, Vidya","Fradkin, Eduardo","Filippini, Jeffrey"],"dc:creator":["Lee, Sangjun"],"dc:date":["2021-09-17T01:10:26Z","2020-12-17","2021-05"],"dc:description":["This Dissertation was approved for publication on 2020-12-17 at 08:47.","DSpace SAF Submission Ingestion Package generated from Vireo submission #16127 on 2021-09-16 at 16:39:02","Made available in DSpace on 2021-09-17T01:10:26Z (GMT). No. of bitstreams: 3 LEE-DISSERTATION-2021.pdf: 18629262 bytes, checksum: 4d3b262167e16ead0650c065d63d74cb (MD5) LICENSE.txt: 4208 bytes, checksum: 2dd5a28b5395a037dedb0b3fa2f75158 (MD5) PROQUEST_LICENSE.txt: 4554 bytes, checksum: 4e7a4e4bdb388c4749df18263c8f136d (MD5) Previous issue date: 2020-12-17","The phase diagrams of unconventional superconductors exhibit many different broken-symmetry phases near superconductivity, such as antiferromagnetism, charge density wave, spin density wave, and nematic order. The proximity and similar temperature scales of these orders suggest superconductivity and other order parameters are intertwined, and how they intertwine is a longstanding problem in condensed matter physics. Among the phases found in the vicinity of superconductivity, charge density wave (CDW) has been found in nearly all cuprate superconductors and observed to have an intimate relationship with superconductivity. Thus, characterizing the nature of CDWs is crucial for understanding the mechanism of unconventional superconductivity. Here, we studied CDWs in cuprate and pnictide superconductors using various x-ray scattering techniques. We discovered new CDW phases in BaNi2As2 and Co-, Sr-doped systems, confirming a generic presence of CDW in the phase diagram of unconventional superconductors, and the nature of the superconductivity in these systems are closely related to the presence of CDW. We also precisely measured the temperature and doping evolution of the CDW wave vector in La1.8-xEu0.2SrxCuO4, revealing the effect of the finite charge compressibility and the coupling of charge and spin order on the wave vector change. Furthermore, energy- and time-resolved resonant soft x-ray scattering experiments on the CDW in La2-xBaxCuO4 were performed to reveal a previously unidentified fluctuating nature of the CDW.","Submission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2021-09-16 without embargo terms","The student, Sangjun Lee, accepted the attached license on 2020-12-15 at 21:07.","The student, Sangjun Lee, submitted this Dissertation for approval on 2020-12-15 at 21:20."],"dc:format":["application/pdf"],"dc:identifier":["http://hdl.handle.net/2142/110401"],"dc:language":["en"],"dc:rights":["Copyright 2021 Sangjun Lee"],"dc:subject":["Superconductor","Unconventional superconductors","Charge density wave","X-ray scattering","Resonant soft x-ray scattering"],"dc:title":["X-ray scattering studies of charge density waves in cuprate and pnictide superconductors"],"dc:type":["text","Thesis"],"thesis:degree_discipline":["Physics"],"thesis:degree_level":["Dissertation"],"thesis:degree_name":["Ph.D."],"thesis:institution_name":["University of Illinois at Urbana-Champaign"]},"updated_at":"2026-07-22T22:24:50Z"}