{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/23470"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/23470","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Quantum saturation and condensation of excitons in copper (I) oxide","abstract":"\"Recent experiments on high-density excitons in Cu$\\sb2$O provide evidence for degenerate quantum statistics and Bose-Einstein condensation of this nearly ideal gas. We model the time dependence of this bosonic system including exciton decay mechanisms, energy exchange with phonons, and interconversion between ortho (triplet-state) and para (singlet-state) excitons, using parameters for the excitonic decay, the coupling to acoustic and low-lying optical phonons, Auger recombination, and ortho-para interconversion derived from experiment. The single adjustable parameter in our model is the optical-phonon cooling rate for Auger and laser-produced hot excitons. We show that the orthoexcitons move along the phase boundary without crossing it (i.e., exhibit a \"\"quantum saturation\"\"), as a consequence of the balance of entropy changes due to cooling of excitons by phonons and heating by the non-radiative Auger two-exciton recombination process. Our study implies that the Auger annihilation rate for para-para collisions is much smaller than that for ortho-para and ortho-ortho collisions due to the band structure of the material, explaining why, under the given experimental conditions, the paraexcitons condense while the orthoexcitons fail to do so. Furthermore, we review the band structure underlying the properties of excitons in Cu$\\sb2$O and connect these properties to the Auger recombination process of excitons.\"","abstract_html":""Recent experiments on high-density excitons in Cu$\\sb2$O provide evidence for degenerate quantum statistics and Bose-Einstein condensation of this nearly ideal gas. We model the time dependence of this bosonic system including exciton decay mechanisms, energy exchange with phonons, and interconversion between ortho (triplet-state) and para (singlet-state) excitons, using parameters for the excitonic decay, the coupling to acoustic and low-lying optical phonons, Auger recombination, and ortho-para interconversion derived from experiment. The single adjustable parameter in our model is the optical-phonon cooling rate for Auger and laser-produced hot excitons. We show that the orthoexcitons move along the phase boundary without crossing it (i.e., exhibit a ""quantum saturation""), as a consequence of the balance of entropy changes due to cooling of excitons by phonons and heating by the non-radiative Auger two-exciton recombination process. Our study implies that the Auger annihilation rate for para-para collisions is much smaller than that for ortho-para and ortho-ortho collisions due to the band structure of the material, explaining why, under the given experimental conditions, the paraexcitons condense while the orthoexcitons fail to do so. Furthermore, we review the band structure underlying the properties of excitons in Cu$\\sb2$O and connect these properties to the Auger recombination process of excitons."","abstract_has_math":true,"creators":["Kavoulakis, Georgios"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Physics, Condensed Matter","degree_department":null,"school":null,"contributors":["Baym, Gordon A."],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2011,"date_issued":"2011-05-07T14:15:23Z","date_published":"2011-05-07T14:15:23Z","updated_at":"2026-07-22T22:25:22Z","subjects":["Physics, Condensed Matter"],"languages":["eng"],"rights":["Copyright 1996 Kavoulakis, Georgios"],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["9780591088007","AAI9702557","(UMI)AAI9702557"],"render_values":[{"text":"9780591088007","href":null,"code":true},{"text":"AAI9702557","href":null,"code":true},{"text":"(UMI)AAI9702557","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/2142/23470","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Baym, Gordon A."]},{"key":"dc:creator","label":"Author","values":["Kavoulakis, Georgios"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2011-05-07T14:15:23Z","10000-01-01","1996"]},{"key":"dc:type","label":"Dc Type","values":["text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Physics, Condensed Matter"]},{"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":["Physics, Condensed Matter"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["eng"]},{"key":"dc:rights","label":"Dc Rights","values":["Copyright 1996 Kavoulakis, Georgios"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["9780591088007","AAI9702557","(UMI)AAI9702557","http://hdl.handle.net/2142/23470"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["\"Recent experiments on high-density excitons in Cu$\\sb2$O provide evidence for degenerate quantum statistics and Bose-Einstein condensation of this nearly ideal gas. We model the time dependence of this bosonic system including exciton decay mechanisms, energy exchange with phonons, and interconversion between ortho (triplet-state) and para (singlet-state) excitons, using parameters for the excitonic decay, the coupling to acoustic and low-lying optical phonons, Auger recombination, and ortho-para interconversion derived from experiment. The single adjustable parameter in our model is the optical-phonon cooling rate for Auger and laser-produced hot excitons. We show that the orthoexcitons move along the phase boundary without crossing it (i.e., exhibit a \"\"quantum saturation\"\"), as a consequence of the balance of entropy changes due to cooling of excitons by phonons and heating by the non-radiative Auger two-exciton recombination process. Our study implies that the Auger annihilation rate for para-para collisions is much smaller than that for ortho-para and ortho-ortho collisions due to the band structure of the material, explaining why, under the given experimental conditions, the paraexcitons condense while the orthoexcitons fail to do so. Furthermore, we review the band structure underlying the properties of excitons in Cu$\\sb2$O and connect these properties to the Auger recombination process of excitons.\"","Made available in DSpace on 2011-05-07T14:15:23Z (GMT). No. of bitstreams: 2 license.txt: 4922 bytes, checksum: 910b249b4beec47e7ab768910c8f966f (MD5) 9702557.pdf: 3656770 bytes, checksum: 98e6c596c19d3a9abc35c3c9bd161eef (MD5) Previous issue date: 1996","Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Howard Ding (hding2@illinois.edu) on 2011-05-07T15:04:41Z Item is restricted indefinitely.","Restriction data tranferred 2014-07-01T11:30:56-05:00 Original Data Group with Access UIUC Users [automated] Release Date: none Reason: ETDs are only available to UIUC Users without author permission","ETDs are only available to UIUC Users without author permission","U of I Only"]},{"key":"dc:title","label":"Title","values":["Quantum saturation and condensation of excitons in copper (I) oxide"]}]}],"canonical_facts":{"dc:contributor":["Baym, Gordon A."],"dc:creator":["Kavoulakis, Georgios"],"dc:date":["2011-05-07T14:15:23Z","10000-01-01","1996"],"dc:description":["\"Recent experiments on high-density excitons in Cu$\\sb2$O provide evidence for degenerate quantum statistics and Bose-Einstein condensation of this nearly ideal gas. We model the time dependence of this bosonic system including exciton decay mechanisms, energy exchange with phonons, and interconversion between ortho (triplet-state) and para (singlet-state) excitons, using parameters for the excitonic decay, the coupling to acoustic and low-lying optical phonons, Auger recombination, and ortho-para interconversion derived from experiment. The single adjustable parameter in our model is the optical-phonon cooling rate for Auger and laser-produced hot excitons. We show that the orthoexcitons move along the phase boundary without crossing it (i.e., exhibit a \"\"quantum saturation\"\"), as a consequence of the balance of entropy changes due to cooling of excitons by phonons and heating by the non-radiative Auger two-exciton recombination process. Our study implies that the Auger annihilation rate for para-para collisions is much smaller than that for ortho-para and ortho-ortho collisions due to the band structure of the material, explaining why, under the given experimental conditions, the paraexcitons condense while the orthoexcitons fail to do so. Furthermore, we review the band structure underlying the properties of excitons in Cu$\\sb2$O and connect these properties to the Auger recombination process of excitons.\"","Made available in DSpace on 2011-05-07T14:15:23Z (GMT). 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