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Exploring Topology in Epitaxial Thin Films of Topological Magnets
Exploring Topology in Epitaxial Thin Films of Topological Magnets
상세정보
- 자료유형
- 학위논문 서양
- 최종처리일시
- 20250211153107
- ISBN
- 9798384088950
- DDC
- 530
- 저자명
- Cheng, Shuyu.
- 서명/저자
- Exploring Topology in Epitaxial Thin Films of Topological Magnets
- 발행사항
- [Sl] : The Ohio State University, 2024
- 발행사항
- Ann Arbor : ProQuest Dissertations & Theses, 2024
- 형태사항
- 268 p
- 주기사항
- Source: Dissertations Abstracts International, Volume: 86-04, Section: B.
- 주기사항
- Advisor: Kawakami, Roland.
- 학위논문주기
- Thesis (Ph.D.)--The Ohio State University, 2024.
- 초록/해제
- 요약The concept of "topology" provides a new merit for categorizing materials based on the properties that are not changed under continuous transforms. The introduction of this concept into condensed matter physics has led to the prediction and realization of many exotic quantum states in both momentum space and real space. In momentum space, two topologically distinct insulating states are expected to have a well-defined boundary where a metallic state emerges. In terms of material selection, the kagome lattice inherently manifests Dirac cones and flat bands, which becomes topologically nontrivial in the presence of spin-orbit coupling. In real space, the concept of topology can be used to classify different distributions of order parameters, and the ones with nonzero winding numbers are expected to be more stable since they are topologically protected. The magnetic skyrmions, as prototypical spin textures with a winding number of ?1, are of particular interest for next-generation memory and logic devices.This thesis aims to demonstrate that the nontrivial topology can be realized in thin films via epitaxial growth, where molecular beam epitaxy (MBE) plays a crucial role in controlling the sample structure at the atomic scale. Using MBE, we have synthesized thin films of kagome materials with different magnetic orderings: ferromagnetic Fe3Sn2 (Chapter 3), paramagnetic CoSn (Chapter 4). and ferrimagnetic RMn6Sn6 (Chapter 5), and the magnetic properties of these materials are studied using a combination of the magneto-optical Kerr effect (MOKE) and the superconducting quantum interference device (SQUID) magnetometer. In CoSn, we have directly observed topologically non-trivial flat bands using synchrotron-based angle-resolved photoemission spectroscopy (ARPES). We have also established a quantitative connection between the band structures and the transport properties of CoSn by a semiclassical transport theory. In Chapter 6, we show that the real-space topology can also be manipulated via thin film synthesis. The magnetic properties of [Pt/Co/Cu]N multilayers can be vastly tuned by varying the sample structures, and magnetic skyrmions are observed in those samples with zero-field multidomain states. Finally, in Chapter 7, we will discuss the time- and angle-resolved photoemission spectroscopy at the National Extreme Ultrafast Science (NeXUS) facility, which will become a formidable machine for investigating and manipulating the band topology.
- 일반주제명
- Physics
- 일반주제명
- Condensed matter physics
- 일반주제명
- Physical chemistry
- 일반주제명
- Materials science
- 키워드
- Band topology
- 기타저자
- The Ohio State University Physics
- 기본자료저록
- Dissertations Abstracts International. 86-04B.
- 전자적 위치 및 접속
- 로그인 후 원문을 볼 수 있습니다.
MARC
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■00520250211153107
■006m o d
■007cr#unu||||||||
■020 ▼a9798384088950
■035 ▼a(MiAaPQ)AAI31674379
■035 ▼a(MiAaPQ)OhioLINKosu171222181554275
■040 ▼aMiAaPQ▼cMiAaPQ
■0820 ▼a530
■1001 ▼aCheng, Shuyu.
■24510▼aExploring Topology in Epitaxial Thin Films of Topological Magnets
■260 ▼a[Sl]▼bThe Ohio State University▼c2024
■260 1▼aAnn Arbor▼bProQuest Dissertations & Theses▼c2024
■300 ▼a268 p
■500 ▼aSource: Dissertations Abstracts International, Volume: 86-04, Section: B.
■500 ▼aAdvisor: Kawakami, Roland.
■5021 ▼aThesis (Ph.D.)--The Ohio State University, 2024.
■520 ▼aThe concept of "topology" provides a new merit for categorizing materials based on the properties that are not changed under continuous transforms. The introduction of this concept into condensed matter physics has led to the prediction and realization of many exotic quantum states in both momentum space and real space. In momentum space, two topologically distinct insulating states are expected to have a well-defined boundary where a metallic state emerges. In terms of material selection, the kagome lattice inherently manifests Dirac cones and flat bands, which becomes topologically nontrivial in the presence of spin-orbit coupling. In real space, the concept of topology can be used to classify different distributions of order parameters, and the ones with nonzero winding numbers are expected to be more stable since they are topologically protected. The magnetic skyrmions, as prototypical spin textures with a winding number of ?1, are of particular interest for next-generation memory and logic devices.This thesis aims to demonstrate that the nontrivial topology can be realized in thin films via epitaxial growth, where molecular beam epitaxy (MBE) plays a crucial role in controlling the sample structure at the atomic scale. Using MBE, we have synthesized thin films of kagome materials with different magnetic orderings: ferromagnetic Fe3Sn2 (Chapter 3), paramagnetic CoSn (Chapter 4). and ferrimagnetic RMn6Sn6 (Chapter 5), and the magnetic properties of these materials are studied using a combination of the magneto-optical Kerr effect (MOKE) and the superconducting quantum interference device (SQUID) magnetometer. In CoSn, we have directly observed topologically non-trivial flat bands using synchrotron-based angle-resolved photoemission spectroscopy (ARPES). We have also established a quantitative connection between the band structures and the transport properties of CoSn by a semiclassical transport theory. In Chapter 6, we show that the real-space topology can also be manipulated via thin film synthesis. The magnetic properties of [Pt/Co/Cu]N multilayers can be vastly tuned by varying the sample structures, and magnetic skyrmions are observed in those samples with zero-field multidomain states. Finally, in Chapter 7, we will discuss the time- and angle-resolved photoemission spectroscopy at the National Extreme Ultrafast Science (NeXUS) facility, which will become a formidable machine for investigating and manipulating the band topology.
■590 ▼aSchool code: 0168.
■650 4▼aPhysics
■650 4▼aCondensed matter physics
■650 4▼aPhysical chemistry
■650 4▼aMaterials science
■653 ▼aTopological materials
■653 ▼aMagnetic skyrmions
■653 ▼aMolecular beam epitaxy
■653 ▼aAngle-resolved photoemission spectroscopy
■653 ▼aBand topology
■690 ▼a0611
■690 ▼a0605
■690 ▼a0794
■690 ▼a0494
■71020▼aThe Ohio State University▼bPhysics.
■7730 ▼tDissertations Abstracts International▼g86-04B.
■790 ▼a0168
■791 ▼aPh.D.
■792 ▼a2024
■793 ▼aEnglish
■85640▼uhttp://www.riss.kr/pdu/ddodLink.do?id=T17164954▼nKERIS▼z이 자료의 원문은 한국교육학술정보원에서 제공합니다.
