{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/49590"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/49590","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Emergence of charge density wave domain walls above the superconducting dome in TiSe2","abstract":"Superconductivity (SC) in so-called “unconventional superconductors” is nearly always found in the vicinity of another ordered state, such as antiferromagnetism, charge density wave (CDW), or stripe order. This suggests a fundamental connection between SC and fluctuations in some other order parameter. 1T-TiSe2 is a prototypical CDW material in the transtion-metal dichalcogenide family and was previously shown to exhibit SC when the CDW is suppressed by hydrostatic pressure or intercalation of Cu atoms. Here, we present detailed high pressure x-ray scattering study on 1T-TiSe2. We found that the CDW phase of 1T-TiSe2 is completely suppressed on the application of hydrostatic pressure and established the existence of a quantum critical point (QCP) at $P_c = 5.1 +- 0.2 GPa, which is more than 1 GPa beyond the end of the SC region. Unexpectedly, at P = 3 GPa we observed a weakly first order, incommensurate CDW phase, suggesting the presence of a Lifshitz tricritical point somewhere above the superconducting dome. Our study suggests that SC in 1T-TiSe2 may not be directly connected to the QCP of the CDW order, but to the formation of CDW domain walls.","abstract_html":"Superconductivity (SC) in so-called “unconventional superconductors” is nearly always found in the vicinity of another ordered state, such as antiferromagnetism, charge density wave (CDW), or stripe order. This suggests a fundamental connection between SC and fluctuations in some other order parameter. 1T-TiSe2 is a prototypical CDW material in the transtion-metal dichalcogenide family and was previously shown to exhibit SC when the CDW is suppressed by hydrostatic pressure or intercalation of Cu atoms. Here, we present detailed high pressure x-ray scattering study on 1T-TiSe2. We found that the CDW phase of 1T-TiSe2 is completely suppressed on the application of hydrostatic pressure and established the existence of a quantum critical point (QCP) at $P_c = 5.1 +- 0.2 GPa, which is more than 1 GPa beyond the end of the SC region. Unexpectedly, at P = 3 GPa we observed a weakly first order, incommensurate CDW phase, suggesting the presence of a Lifshitz tricritical point somewhere above the superconducting dome. Our study suggests that SC in 1T-TiSe2 may not be directly connected to the QCP of the CDW order, but to the formation of CDW domain walls.","abstract_has_math":false,"creators":["Joe, Young Il"],"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 M.","Chiang, Tai-Chang","Phillips, Philip W.","Grosse Perdekamp, Matthias"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2014,"date_issued":"2014-05-30T16:51:23Z","date_published":"2014-05-30T16:51:23Z","updated_at":"2026-07-22T22:25:38Z","subjects":["charge density wave","incommensurate charge density wave","domain wall","X-ray diffraction","transition metal dichacogenide","superconductivity","high pressure","low temperature"],"languages":["en"],"rights":["Copyright 2014 Young Il Joe"],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/2142/49590","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Abbamonte, Peter M.","Chiang, Tai-Chang","Phillips, Philip W.","Grosse Perdekamp, Matthias"]},{"key":"dc:creator","label":"Author","values":["Joe, Young Il"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2014-05-30T16:51:23Z","2014-05"]},{"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":["charge density wave","incommensurate charge density wave","domain wall","X-ray diffraction","transition metal dichacogenide","superconductivity","high pressure","low temperature"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["Copyright 2014 Young Il Joe"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["http://hdl.handle.net/2142/49590"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Superconductivity (SC) in so-called “unconventional superconductors” is nearly always found in the vicinity of another ordered state, such as antiferromagnetism, charge density wave (CDW), or stripe order. This suggests a fundamental connection between SC and fluctuations in some other order parameter. 1T-TiSe2 is a prototypical CDW material in the transtion-metal dichalcogenide family and was previously shown to exhibit SC when the CDW is suppressed by hydrostatic pressure or intercalation of Cu atoms. Here, we present detailed high pressure x-ray scattering study on 1T-TiSe2. We found that the CDW phase of 1T-TiSe2 is completely suppressed on the application of hydrostatic pressure and established the existence of a quantum critical point (QCP) at $P_c = 5.1 +- 0.2 GPa, which is more than 1 GPa beyond the end of the SC region. Unexpectedly, at P = 3 GPa we observed a weakly first order, incommensurate CDW phase, suggesting the presence of a Lifshitz tricritical point somewhere above the superconducting dome. Our study suggests that SC in 1T-TiSe2 may not be directly connected to the QCP of the CDW order, but to the formation of CDW domain walls.","Item withdrawn by Laura Spradlin (lspradl2@illinois.edu) on 2014-03-27T13:22:21Z Item was in collections: University of Illinois Theses & Dissertations (ID: 1) No. of bitstreams: 2 Joe_YoungIl.tex: 141476 bytes, checksum: b46ffea5923ebfb5fa82a6c12e5368c0 (MD5) Joe_YoungIl.pdf: 10710729 bytes, checksum: 6504153e23580982e9b4828254fdb9cb (MD5)","Made available in DSpace on 2014-05-30T16:51:23Z (GMT). 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This suggests a fundamental connection between SC and fluctuations in some other order parameter. 1T-TiSe2 is a prototypical CDW material in the transtion-metal dichalcogenide family and was previously shown to exhibit SC when the CDW is suppressed by hydrostatic pressure or intercalation of Cu atoms. Here, we present detailed high pressure x-ray scattering study on 1T-TiSe2. We found that the CDW phase of 1T-TiSe2 is completely suppressed on the application of hydrostatic pressure and established the existence of a quantum critical point (QCP) at $P_c = 5.1 +- 0.2 GPa, which is more than 1 GPa beyond the end of the SC region. Unexpectedly, at P = 3 GPa we observed a weakly first order, incommensurate CDW phase, suggesting the presence of a Lifshitz tricritical point somewhere above the superconducting dome. Our study suggests that SC in 1T-TiSe2 may not be directly connected to the QCP of the CDW order, but to the formation of CDW domain walls.","Item withdrawn by Laura Spradlin (lspradl2@illinois.edu) on 2014-03-27T13:22:21Z Item was in collections: University of Illinois Theses & Dissertations (ID: 1) No. of bitstreams: 2 Joe_YoungIl.tex: 141476 bytes, checksum: b46ffea5923ebfb5fa82a6c12e5368c0 (MD5) Joe_YoungIl.pdf: 10710729 bytes, checksum: 6504153e23580982e9b4828254fdb9cb (MD5)","Made available in DSpace on 2014-05-30T16:51:23Z (GMT). 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