WEKO3
Item
Imaging Monopoles in Spin Ice via Electron Holography
https://doi.org/10.15102/1394.00001789
https://doi.org/10.15102/1394.000017895e925a90-2cc3-4f91-a0d5-8c5094fe2ffc
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Full_Text (36.8 MB)
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Final_Exam_Abstract (42.9 kB)
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| Item type | 学位論文 / Thesis or Dissertation(1) | |||||||
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| PubDate | 2021-03-19 | |||||||
| Title | ||||||||
| 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 | |||||||
| Language | ja | |||||||
| Title | ||||||||
| Title | Imaging Monopoles in Spin Ice via Electron Holography | |||||||
| Language | en | |||||||
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| Language | eng | |||||||
| Resource Type | ||||||||
| Resource Type Identifier | http://purl.org/coar/resource_type/c_db06 | |||||||
| Resource Type | doctoral thesis | |||||||
| Identifier Registration | ||||||||
| Identifier Registration | 10.15102/1394.00001789 | |||||||
| Identifier Registration Type | JaLC | |||||||
| Access Right | ||||||||
| Access Rights | open access | |||||||
| Access Rights URI | http://purl.org/coar/access_right/c_abf2 | |||||||
| Author |
Dhar, Ankur
× Dhar, Ankur
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| Abstract | ||||||||
| Description Type | Other | |||||||
| Description | 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. | |||||||
| Language | en | |||||||
| Exam Date | ||||||||
| 2020-07-27 | ||||||||
| Degree Conferral Date | ||||||||
| Date Granted | 2020-08-31 | |||||||
| Degree | ||||||||
| Degree Name | Doctor of Philosophy | |||||||
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| Dissertation Number | 甲第58号 | |||||||
| Degree Conferrral Institution | ||||||||
| Degree Grantor Name Identifier Scheme | kakenhi | |||||||
| Degree Grantor Name Identifier | 38005 | |||||||
| Degree Grantor Name | Okinawa Institute of Science and Technology Graduate University | |||||||
| Version Format | ||||||||
| Version Type | VoR | |||||||
| Version Type Resource | http://purl.org/coar/version/c_970fb48d4fbd8a85 | |||||||
| Copyright Information | ||||||||
| Rights | © 2020 The Author. | |||||||
