{"id":{"repo_id":"buffalo","oai_identifier":"oai:ubir.buffalo.edu:10477/86707"},"canonical_url":"https://search.dev.ndltd.org/etd/buffalo/oai:ubir.buffalo.edu:10477/86707","repository":{"repo_id":"buffalo","name":"Buffalo","base_url":"https://ubir.buffalo.edu/oai/request"},"display":{"title":"Large-Scale GW Quasiparticle Calculations for 3D and 2D Materials: Methodology Development and Applications","abstract":"Ph.D.","abstract_html":"Ph.D.","abstract_has_math":false,"creators":["Xia, Weiyi; 0000-0001-7669-6305"],"institution":"State University of New York at Buffalo","degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":["Zhang, Peihong","Physics"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2025,"date_issued":"2025-02-21T21:36:41Z","date_published":"2025-02-21T21:36:41Z","updated_at":"2026-07-27T19:05:34Z","subjects":["physics"],"languages":["eng"],"rights":["Users of works found in University at Buffalo Institutional Repository (UBIR) are responsible for identifying and contacting the copyright owner for permission to reuse. University at Buffalo Libraries do not manage rights for copyright-protected works and cannot assist with permissions.","Copyright retained by author."],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/10477/86707","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Zhang, Peihong","Physics"]},{"key":"dc:creator","label":"Author","values":["Xia, Weiyi; 0000-0001-7669-6305"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2025-02-21T21:36:41Z","2020"]},{"key":"dc:publisher","label":"Institution","values":["State University of New York at Buffalo"]},{"key":"dc:type","label":"Dc Type","values":["Text","Dissertation"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["physics"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["eng"]},{"key":"dc:rights","label":"Dc Rights","values":["Users of works found in University at Buffalo Institutional Repository (UBIR) are responsible for identifying and contacting the copyright owner for permission to reuse. University at Buffalo Libraries do not manage rights for copyright-protected works and cannot assist with permissions.","Copyright retained by author."]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["http://hdl.handle.net/10477/86707"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Ph.D.","Understanding the excited states properties of materials has been and still is a central topic in condensed matter physics because of its fundamental and technological importance. Unfortunately, accurate and efficient theoretical calculations of the excited states properties of complex materials still pose significant challenges due to the unfordable scaling of the computational cost with respect to system size and complications of numerical convergence issues. Recently, two dimensional (2D) materials have attracted unprecedented research interest due to their extraordinary physical properties and potential uses in a wide-range of applications. Surprisingly, accurate calculations of the excited states properties of 2D materials poses far greater challenges compared with bulk (3D) solids. This thesis aims at developing computational methods for accurate and efficient calculations of complex bulk and 2D solids within the GW approximation, and the application of these new development to the understanding and prediction of the excited states properties of a wide range of 2D and 3D solids. Our methods promise a speed-up factor of up to two orders of magnitude for the GW quasiparticle calculations of large/complex 3D solids. For 2D materials, we have achieved a speed-up factor of up to three orders of magnitude. Using these newly developed methods, we have investigated the engineering of the near-edge electronic structure of layered material SnSe through Strains; we have also predicted the quasiparticle band structure of C3N and C3B, two recently discovered 2D materials, and those of 2D C2N and hexagonal BN (hBN). Finally, we investigate the possibility designing continuously tunable band gap 2D materials forming graphene-hBN lateral superlattices.","**To request an accessible version of the file(s) associated with this item, contact library@buffalo.edu. Please include the item's persistent URL [http://hdl.handle.net/. . .] in your request.**"]},{"key":"dc:format","label":"Dc Format","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Large-Scale GW Quasiparticle Calculations for 3D and 2D Materials: Methodology Development and Applications"]}]}],"canonical_facts":{"dc:contributor":["Zhang, Peihong","Physics"],"dc:creator":["Xia, Weiyi; 0000-0001-7669-6305"],"dc:date":["2025-02-21T21:36:41Z","2020"],"dc:description":["Ph.D.","Understanding the excited states properties of materials has been and still is a central topic in condensed matter physics because of its fundamental and technological importance. Unfortunately, accurate and efficient theoretical calculations of the excited states properties of complex materials still pose significant challenges due to the unfordable scaling of the computational cost with respect to system size and complications of numerical convergence issues. Recently, two dimensional (2D) materials have attracted unprecedented research interest due to their extraordinary physical properties and potential uses in a wide-range of applications. Surprisingly, accurate calculations of the excited states properties of 2D materials poses far greater challenges compared with bulk (3D) solids. This thesis aims at developing computational methods for accurate and efficient calculations of complex bulk and 2D solids within the GW approximation, and the application of these new development to the understanding and prediction of the excited states properties of a wide range of 2D and 3D solids. Our methods promise a speed-up factor of up to two orders of magnitude for the GW quasiparticle calculations of large/complex 3D solids. For 2D materials, we have achieved a speed-up factor of up to three orders of magnitude. Using these newly developed methods, we have investigated the engineering of the near-edge electronic structure of layered material SnSe through Strains; we have also predicted the quasiparticle band structure of C3N and C3B, two recently discovered 2D materials, and those of 2D C2N and hexagonal BN (hBN). Finally, we investigate the possibility designing continuously tunable band gap 2D materials forming graphene-hBN lateral superlattices.","**To request an accessible version of the file(s) associated with this item, contact library@buffalo.edu. Please include the item's persistent URL [http://hdl.handle.net/. . .] in your request.**"],"dc:format":["application/pdf"],"dc:identifier":["http://hdl.handle.net/10477/86707"],"dc:language":["eng"],"dc:publisher":["State University of New York at Buffalo"],"dc:rights":["Users of works found in University at Buffalo Institutional Repository (UBIR) are responsible for identifying and contacting the copyright owner for permission to reuse. University at Buffalo Libraries do not manage rights for copyright-protected works and cannot assist with permissions.","Copyright retained by author."],"dc:subject":["physics"],"dc:title":["Large-Scale GW Quasiparticle Calculations for 3D and 2D Materials: Methodology Development and Applications"],"dc:type":["Text","Dissertation"]},"updated_at":"2026-07-27T19:05:34Z"}