{"id":{"repo_id":"heriot-watt","oai_identifier":"oai:ros.hw.ac.uk:10399/4732"},"canonical_url":"https://search.dev.ndltd.org/etd/heriot-watt/oai:ros.hw.ac.uk:10399/4732","repository":{"repo_id":"heriot-watt","name":"Heriot-Watt University","base_url":"https://www.ros.hw.ac.uk/oai/request"},"display":{"title":"Optical investigation of many-body interactions in transition metal dichalcogenide heterostructures","abstract":"Two-dimensional transition metal dichalcogenide (TMD) heterostructures have emerged as a novel platform for the investigation of many-body physical phenomena. In these systems, tightly bound excitons dressed by a gate-tunable Fermi sea form exciton-polarons, which are sensitive to Coulomb and spin interactions. In addition, TMD moir´e devices provide a highly tunable platform to study strongly correlated electronic states. This thesis describes the use of magneto-optical polarisation-resolved white-light confocal reflection spectroscopy at cryogenic temperatures (4 K) to probe different many-body interactions in TMD heterostructure devices. First, monolayer and bilayer tungsten diselenide (WSe2) and molybdenum diselenide (MoSe2) are investigated under varying carrier concentration. The doping dependent dispersions of the exciton-polarons are shown to be excellent probes of the distinctive band structures of these materials. Then, in a moir´e heterobilayer MoSe2/WSe2 structure, optically injected excitons are shown to interact with itinerant carriers occupying narrow moir´e bands to form exciton-polarons sensitive to strong correlations. At a multitude of fractional fillings of the moir´e lattice, the ordering of both electrons and holes into stable correlated electronic states is observed, leading to extraordinary Zeeman splittings of the exciton-polarons. Next, in heterotrilayer bilayer WSe2/monolayer MoSe2, the energetic ordering of the moir´e bands is shown to be highly tunable with applied vertical electric field, leading to the demonstration of hole transfer between correlated states in K and Γ valley derived moir´e bands. Finally, the moire lattice uniformity of MoSe2/WSe2 moir´e heterostructures is probed by spatial mapping of the electronic correlations, leading to a measured variation in twist angle of 0.6 degrees across the device. These results establish WSe2 and MoSe2 heterostructures as an exciting platform for investigations of exciton-polarons, Fermi-Hubbard or Bose-Hubbard physics.","abstract_html":"Two-dimensional transition metal dichalcogenide (TMD) heterostructures have emerged as a novel platform for the investigation of many-body physical phenomena. In these systems, tightly bound excitons dressed by a gate-tunable Fermi sea form exciton-polarons, which are sensitive to Coulomb and spin interactions. In addition, TMD moir´e devices provide a highly tunable platform to study strongly correlated electronic states. This thesis describes the use of magneto-optical polarisation-resolved white-light confocal reflection spectroscopy at cryogenic temperatures (4 K) to probe different many-body interactions in TMD heterostructure devices. First, monolayer and bilayer tungsten diselenide (WSe2) and molybdenum diselenide (MoSe2) are investigated under varying carrier concentration. The doping dependent dispersions of the exciton-polarons are shown to be excellent probes of the distinctive band structures of these materials. Then, in a moir´e heterobilayer MoSe2/WSe2 structure, optically injected excitons are shown to interact with itinerant carriers occupying narrow moir´e bands to form exciton-polarons sensitive to strong correlations. At a multitude of fractional fillings of the moir´e lattice, the ordering of both electrons and holes into stable correlated electronic states is observed, leading to extraordinary Zeeman splittings of the exciton-polarons. Next, in heterotrilayer bilayer WSe2/monolayer MoSe2, the energetic ordering of the moir´e bands is shown to be highly tunable with applied vertical electric field, leading to the demonstration of hole transfer between correlated states in K and Γ valley derived moir´e bands. Finally, the moire lattice uniformity of MoSe2/WSe2 moir´e heterostructures is probed by spatial mapping of the electronic correlations, leading to a measured variation in twist angle of 0.6 degrees across the device. These results establish WSe2 and MoSe2 heterostructures as an exciting platform for investigations of exciton-polarons, Fermi-Hubbard or Bose-Hubbard physics.","abstract_has_math":false,"creators":["Campbell, Aidan"],"institution":"Heriot-Watt University","degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":["Gerardot, Professor Brian"],"committee_chairs":[],"committee_members":[],"year":2022,"date_issued":"2022-11","date_published":"2022-11","updated_at":"2026-07-24T02:31:07Z","subjects":[],"languages":["en"],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/10399/4732","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Gerardot, Professor Brian"]},{"key":"dc:creator","label":"Author","values":["Campbell, Aidan"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2023-04-21T09:34:09Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2023-04-21T09:34:09Z"]},{"key":"dc:date.issued","label":"Date","values":["2022-11"]},{"key":"dc:publisher","label":"Institution","values":["Heriot-Watt University","Engineering and Physical Sciences"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language.iso","label":"Language (ISO)","values":["en"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/10399/4732"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Two-dimensional transition metal dichalcogenide (TMD) heterostructures have emerged as a novel platform for the investigation of many-body physical phenomena. In these systems, tightly bound excitons dressed by a gate-tunable Fermi sea form exciton-polarons, which are sensitive to Coulomb and spin interactions. In addition, TMD moir´e devices provide a highly tunable platform to study strongly correlated electronic states. This thesis describes the use of magneto-optical polarisation-resolved white-light confocal reflection spectroscopy at cryogenic temperatures (4 K) to probe different many-body interactions in TMD heterostructure devices. First, monolayer and bilayer tungsten diselenide (WSe2) and molybdenum diselenide (MoSe2) are investigated under varying carrier concentration. The doping dependent dispersions of the exciton-polarons are shown to be excellent probes of the distinctive band structures of these materials. Then, in a moir´e heterobilayer MoSe2/WSe2 structure, optically injected excitons are shown to interact with itinerant carriers occupying narrow moir´e bands to form exciton-polarons sensitive to strong correlations. At a multitude of fractional fillings of the moir´e lattice, the ordering of both electrons and holes into stable correlated electronic states is observed, leading to extraordinary Zeeman splittings of the exciton-polarons. Next, in heterotrilayer bilayer WSe2/monolayer MoSe2, the energetic ordering of the moir´e bands is shown to be highly tunable with applied vertical electric field, leading to the demonstration of hole transfer between correlated states in K and Γ valley derived moir´e bands. Finally, the moire lattice uniformity of MoSe2/WSe2 moir´e heterostructures is probed by spatial mapping of the electronic correlations, leading to a measured variation in twist angle of 0.6 degrees across the device. These results establish WSe2 and MoSe2 heterostructures as an exciting platform for investigations of exciton-polarons, Fermi-Hubbard or Bose-Hubbard physics."]},{"key":"dc:title","label":"Title","values":["Optical investigation of many-body interactions in transition metal dichalcogenide heterostructures"]}]}],"canonical_facts":{"dc:contributor.advisor":["Gerardot, Professor Brian"],"dc:creator":["Campbell, Aidan"],"dc:date.accessioned":["2023-04-21T09:34:09Z"],"dc:date.available":["2023-04-21T09:34:09Z"],"dc:date.issued":["2022-11"],"dc:description.abstract":["Two-dimensional transition metal dichalcogenide (TMD) heterostructures have emerged as a novel platform for the investigation of many-body physical phenomena. In these systems, tightly bound excitons dressed by a gate-tunable Fermi sea form exciton-polarons, which are sensitive to Coulomb and spin interactions. In addition, TMD moir´e devices provide a highly tunable platform to study strongly correlated electronic states. This thesis describes the use of magneto-optical polarisation-resolved white-light confocal reflection spectroscopy at cryogenic temperatures (4 K) to probe different many-body interactions in TMD heterostructure devices. First, monolayer and bilayer tungsten diselenide (WSe2) and molybdenum diselenide (MoSe2) are investigated under varying carrier concentration. The doping dependent dispersions of the exciton-polarons are shown to be excellent probes of the distinctive band structures of these materials. Then, in a moir´e heterobilayer MoSe2/WSe2 structure, optically injected excitons are shown to interact with itinerant carriers occupying narrow moir´e bands to form exciton-polarons sensitive to strong correlations. At a multitude of fractional fillings of the moir´e lattice, the ordering of both electrons and holes into stable correlated electronic states is observed, leading to extraordinary Zeeman splittings of the exciton-polarons. Next, in heterotrilayer bilayer WSe2/monolayer MoSe2, the energetic ordering of the moir´e bands is shown to be highly tunable with applied vertical electric field, leading to the demonstration of hole transfer between correlated states in K and Γ valley derived moir´e bands. Finally, the moire lattice uniformity of MoSe2/WSe2 moir´e heterostructures is probed by spatial mapping of the electronic correlations, leading to a measured variation in twist angle of 0.6 degrees across the device. These results establish WSe2 and MoSe2 heterostructures as an exciting platform for investigations of exciton-polarons, Fermi-Hubbard or Bose-Hubbard physics."],"dc:identifier.uri":["http://hdl.handle.net/10399/4732"],"dc:language.iso":["en"],"dc:publisher":["Heriot-Watt University","Engineering and Physical Sciences"],"dc:title":["Optical investigation of many-body interactions in transition metal dichalcogenide heterostructures"],"dc:type":["Thesis"]},"updated_at":"2026-07-24T02:31:07Z"}