電子線ホログラフィーによる、スピンアイス中のモノポール顕微観察への挑戦

• Material Type: 博士論文
• Title: 電子線ホログラフィーによる、スピンアイス中のモノポール顕微観察への挑戦
• Author/Editor: Dhar, Ankur
• Author Heading: Dhar, Ankur
• Publication Date: 2020-08-31
• Publication Date (W3CDTF): 2020-08-31
• Alternative Title: Imaging Monopoles in Spin Ice via Electron Holography
• Degree grantor/type: Okinawa Institute of Science and Technology Graduate University
• Date Granted: 2020-08-31
• Date Granted (W3CDTF): 2020-08-31
• Dissertation Number: 甲第58号
• Degree Type: Doctor of Philosophy
• Conferring No. (Dissertation): 甲第58号
• Text Language Code: eng
• Target Audience: 一般
• Note (General): Originally proposed by Pierre Curie, magnetic monopoles in vacuum have long remained elusive to detection, but recently mergent monopoles of the microscopic H field have been shown to exist in spin ice. As such, they present a valuable testing ground for the physics of magnetic monopoles which remain elusive as high energy particles. However, signatures of monopoles in spin-ice materials have only been indirect so far, and their direct observation has remained an open challenge since their discovery. One such technique that would make this direct observation a reality is electron holography, due to the electron’s high sensitivity to magnetic fields via the Aharonov-Bohm effect. Currently the best holographic microscopes can achieve 3D spatial imaging of spin phenomena with sub-nanometer resolution. In this thesis, I explore the possibility of imaging monopoles with electron holography through experimental measurements of monopole and spin ice analogs and computational simulation of how a monopole would appear in a pyrochlore spin ice thin film. My experimental work focused on measuring the phase signal from an elongated magnetic needle, as well as artificial spin ice formed from a 2D lattice of nanoscale magnets. My simulated results show for the first time what a monopole in pyrochlore spin ice would look like if imaged using electron holography. The experimental and simulation results together help define the technical requirements and experimental signals required to achieve direct observation of magnetic monopoles in spin ice via electron holography.
• DOI: 10.15102/1394.00001789; https://doi.org/10.15102/1394.00001789
• Persistent ID (NDL): info:ndljp/pid/11659562; https://dl.ndl.go.jp/pid/11659562
• Collection: 障害者向け資料
• Collection (Materials For Handicapped People:1): テキストデータ
• Collection (particular): 国立国会図書館デジタルコレクション > デジタル化資料 > 博士論文; https://dl.ndl.go.jp/collections/A00014
• Acquisition Basis: 博士論文（自動収集）
• Date Accepted (W3CDTF): 2021-04-07T03:01:57+09:00
• Date Created (W3CDTF): 2021-03-19
• Format (IMT): application/pdf
• Access Restrictions: 国立国会図書館内限定公開
• Service for the Digitized Contents Transmission Service: 図書館・個人送信対象外
• Availability of remote photoduplication service: 可
• Periodical Title (URI): http://dx.doi.org/10.15102/1394.00001789; https://oist.repo.nii.ac.jp/records/1986
• Data Provider (Database): 国立国会図書館 : 国立国会図書館デジタルコレクション; https://dl.ndl.go.jp