{"id":{"repo_id":"nus","oai_identifier":"oai:scholarbank.nus.edu.sg:10635/195576"},"canonical_url":"https://search.dev.ndltd.org/etd/nus/oai:scholarbank.nus.edu.sg:10635/195576","repository":{"repo_id":"nus","name":"National University of Singapore","base_url":"https://scholarbank.nus.edu.sg/oai/request"},"display":{"title":"SPIN AND CHARGE TRANSPORT IN 2D MATERIALS AND VAN DER WAALS HETEROSTRUCTURES","abstract":"This thesis focuses on the exploration of topological superconductivity in 2D materials and van der Waals heterostructures. Our approach is to realize topological superconductivity in Ising superconductors. A survey of different candidate materials systems for topological superconductivity is presented in this report. We will show that the Ising superconductor approach has many advantages over the forerunner approach — semiconductor/superconductor heterostructure. Preliminary results on a Ising superconductor NbSe2 are presented. Firstly, 2D superconductivity in ultra-thin NbSe2 is verified by fluctuation effects, square root dependence of in-plane upper critical field as well as BKT transition. Secondly, spin-polarized tunnel spectroscopy of NbSe2 is presented. The tunnel spectra strongly depend on the magnetization configuration of the tunnel contacts. The result is drastically different from a similar experiment on aluminium, suggesting the existence of spin supercurrent carried by spin-triplet Cooper pairs in NbSe2. Last but not least, the existence of spin supercurrent is further supported by non-local spin valve measurement. A clear spin signal of magnitude up to 4 Ω was observed. Spin lifetime and diffusion length were extracted from Hanle precession measurement to be 220 ps and 1.81 μm, respectively.","abstract_html":"This thesis focuses on the exploration of topological superconductivity in 2D materials and van der Waals heterostructures. Our approach is to realize topological superconductivity in Ising superconductors. A survey of different candidate materials systems for topological superconductivity is presented in this report. We will show that the Ising superconductor approach has many advantages over the forerunner approach — semiconductor/superconductor heterostructure. Preliminary results on a Ising superconductor NbSe2 are presented. Firstly, 2D superconductivity in ultra-thin NbSe2 is verified by fluctuation effects, square root dependence of in-plane upper critical field as well as BKT transition. Secondly, spin-polarized tunnel spectroscopy of NbSe2 is presented. The tunnel spectra strongly depend on the magnetization configuration of the tunnel contacts. The result is drastically different from a similar experiment on aluminium, suggesting the existence of spin supercurrent carried by spin-triplet Cooper pairs in NbSe2. Last but not least, the existence of spin supercurrent is further supported by non-local spin valve measurement. A clear spin signal of magnitude up to 4 Ω was observed. Spin lifetime and diffusion length were extracted from Hanle precession measurement to be 220 ps and 1.81 μm, respectively.","abstract_has_math":false,"creators":["HUANG JUNYE"],"institution":null,"degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2021,"date_issued":"2021-01-22","date_published":"2021-01-22","updated_at":"2026-07-24T03:31:26Z","subjects":["2d materials, graphene, spintronics, superconductivity, majorana, quantum computing"],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":null,"outbound_label":null,"outbound_source":null},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:creator","label":"Author","values":["HUANG JUNYE"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.issued","label":"Date","values":["2021-01-22"]},{"key":"dc:relation.isreferencedby","label":"Dc Relation Isreferencedby","values":["https://scholarbank.nus.edu.sg/handle/10635/195576"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["2d materials, graphene, spintronics, superconductivity, majorana, quantum computing"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["https://scholarbank.nus.edu.sg/bitstreams/66f405b4-98c4-413b-a089-8dfbbb0b4222/download"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["This thesis focuses on the exploration of topological superconductivity in 2D materials and van der Waals heterostructures. 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Last but not least, the existence of spin supercurrent is further supported by non-local spin valve measurement. A clear spin signal of magnitude up to 4 Ω was observed. Spin lifetime and diffusion length were extracted from Hanle precession measurement to be 220 ps and 1.81 μm, respectively."]},{"key":"dc:format.checksum.md5","label":"Dc Format Checksum Md5","values":["bcb5e96f9c9a47d7d9746abbd5fd8fd4","40b01c34bca7e6f1acc386a3143915ec"]},{"key":"dc:title","label":"Title","values":["SPIN AND CHARGE TRANSPORT IN 2D MATERIALS AND VAN DER WAALS HETEROSTRUCTURES"]}]}],"canonical_facts":{"dc:creator":["HUANG JUNYE"],"dc:date.issued":["2021-01-22"],"dc:description.abstract":["This thesis focuses on the exploration of topological superconductivity in 2D materials and van der Waals heterostructures. Our approach is to realize topological superconductivity in Ising superconductors. A survey of different candidate materials systems for topological superconductivity is presented in this report. We will show that the Ising superconductor approach has many advantages over the forerunner approach — semiconductor/superconductor heterostructure. Preliminary results on a Ising superconductor NbSe2 are presented. Firstly, 2D superconductivity in ultra-thin NbSe2 is verified by fluctuation effects, square root dependence of in-plane upper critical field as well as BKT transition. Secondly, spin-polarized tunnel spectroscopy of NbSe2 is presented. The tunnel spectra strongly depend on the magnetization configuration of the tunnel contacts. The result is drastically different from a similar experiment on aluminium, suggesting the existence of spin supercurrent carried by spin-triplet Cooper pairs in NbSe2. Last but not least, the existence of spin supercurrent is further supported by non-local spin valve measurement. A clear spin signal of magnitude up to 4 Ω was observed. 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