서브메뉴
검색
Investigating the Ground State of Organic Frustrated Magnets Using Nuclear Magnetic Resonance- [electronic resource]
Investigating the Ground State of Organic Frustrated Magnets Using Nuclear Magnetic Resonance- [electronic resource]
상세정보
- 자료유형
- 학위논문파일 국외
- 최종처리일시
- 20240214101239
- ISBN
- 9798379726065
- DDC
- 530
- 저자명
- Le, Teresa H.
- 서명/저자
- Investigating the Ground State of Organic Frustrated Magnets Using Nuclear Magnetic Resonance - [electronic resource]
- 발행사항
- [S.l.]: : University of California, Los Angeles., 2023
- 발행사항
- Ann Arbor : : ProQuest Dissertations & Theses,, 2023
- 형태사항
- 1 online resource(113 p.)
- 주기사항
- Source: Dissertations Abstracts International, Volume: 84-12, Section: B.
- 주기사항
- Advisor: Brown, Stuart.
- 학위논문주기
- Thesis (Ph.D.)--University of California, Los Angeles, 2023.
- 사용제한주기
- This item must not be sold to any third party vendors.
- 초록/해제
- 요약Quantum Spin Liquids (QSLs) are novel, exotic states of matter that have been proposed to be the key to topological quantum computing and high temperature superconductivity. The QSL is defined, in theory, to be a nonmagnetic insulator with quantum disordered, highly entangled spins. Unfortunately, the connection between theory and experiment in this field is still incomplete. While lack of magnetic order is easy to detect experimentally, quantum disorder and long range entanglement are more difficult to prove. Consequently, there are many candidate QSL materials, but there are no undisputed QSLs to date. This dissertation investigates the first quasi-2D QSL candidate ever to be discovered, κ-(BEDT-TTF)2Cu2(CN)3, and its cousins, κ-(BEDT-TTF)2Hg(SCN)2Cl, and κ-(BEDT-TTF)2Hg(SCN)2Br, through the lens of Nuclear Magnetic Resonance (NMR) in an attempt to answer some of the outstanding questions still present almost 20 years after the discovery of κ-(BEDT-TTF)2Cu2(CN)3. First, the effects of charge degrees of freedom on the ground state of κ-(BEDT-TTF)2X materials are examined via the study of κ-(BEDT-TTF)2Hg(SCN)2Cl and κ-(BEDT-TTF)2Hg(SCN)2Br, both of which are more likely to be charge ordered than κ-(BEDT-TTF)2Cu2(CN)3. Then, the question of whether or not the NMR signature of κ-(BEDT-TTF)2Cu2(CN)3 is compatible with a spinon fermi surface and the nature of the "6 K anomaly" in κ-(BEDT-TTF)2Cu2(CN)3 is revisited via low temperature, high field NMR. In the case of κ-(BEDT-TTF)2Hg(SCN)2Cl, it is found that impurity spins dominate the low temperature NMR relaxation signature masking the intrinsic behavior. The 1/T1 relaxation of κ-(BEDT-TTF)2Hg(SCN)2Cl is very similar to that of κ-(BEDT-TTF)2Cu2(CN)3, and it is reasonable to believe the same "masking" may apply in the latter case. κ-(BEDT-TTF)2Hg(SCN)2Br, on the other hand, behaves quite differently from the other two. While none of the materials studied exhibit any signs of long range magnetic order, signatures for short range magnetic order were detected in κ-(BEDT-TTF)2Hg(SCN)2Br. κ-(BEDT-TTF)2Cu2(CN)3 is revisited at high fields in order to test the theory that impurity spins mask intrinsic relaxation behavior, as NMR signatures from impurities should be frozen out at sufficiently high fields. The relaxation signature of κ-(BEDT-TTF)2Cu2(CN)3 is found to be gapped, inconsistent with a spinon fermi surface. The nature of this gap remains unclear. Some exploration into the Inverse Laplace Transform (ILT) method as a tool for analyzing the stretched exponential in the context of κ-(BEDT-TTF)2Cu2(CN)3 is discussed as well.
- 일반주제명
- Applied physics.
- 일반주제명
- Theoretical physics.
- 기타저자
- University of California, Los Angeles Physics 0666
- 기본자료저록
- Dissertations Abstracts International. 84-12B.
- 기본자료저록
- Dissertation Abstract International
- 전자적 위치 및 접속
- 로그인 후 원문을 볼 수 있습니다.
MARC
008240612s2023 us |||||||||||||||c||eng d■001000016933377
■00520240214101239
■006m o d
■007cr#unu||||||||
■020 ▼a9798379726065
■035 ▼a(MiAaPQ)AAI30528284
■040 ▼aMiAaPQ▼cMiAaPQ
■0820 ▼a530
■1001 ▼aLe, Teresa H.
■24510▼aInvestigating the Ground State of Organic Frustrated Magnets Using Nuclear Magnetic Resonance▼h[electronic resource]
■260 ▼a[S.l.]:▼bUniversity of California, Los Angeles. ▼c2023
■260 1▼aAnn Arbor :▼bProQuest Dissertations & Theses, ▼c2023
■300 ▼a1 online resource(113 p.)
■500 ▼aSource: Dissertations Abstracts International, Volume: 84-12, Section: B.
■500 ▼aAdvisor: Brown, Stuart.
■5021 ▼aThesis (Ph.D.)--University of California, Los Angeles, 2023.
■506 ▼aThis item must not be sold to any third party vendors.
■520 ▼aQuantum Spin Liquids (QSLs) are novel, exotic states of matter that have been proposed to be the key to topological quantum computing and high temperature superconductivity. The QSL is defined, in theory, to be a nonmagnetic insulator with quantum disordered, highly entangled spins. Unfortunately, the connection between theory and experiment in this field is still incomplete. While lack of magnetic order is easy to detect experimentally, quantum disorder and long range entanglement are more difficult to prove. Consequently, there are many candidate QSL materials, but there are no undisputed QSLs to date. This dissertation investigates the first quasi-2D QSL candidate ever to be discovered, κ-(BEDT-TTF)2Cu2(CN)3, and its cousins, κ-(BEDT-TTF)2Hg(SCN)2Cl, and κ-(BEDT-TTF)2Hg(SCN)2Br, through the lens of Nuclear Magnetic Resonance (NMR) in an attempt to answer some of the outstanding questions still present almost 20 years after the discovery of κ-(BEDT-TTF)2Cu2(CN)3. First, the effects of charge degrees of freedom on the ground state of κ-(BEDT-TTF)2X materials are examined via the study of κ-(BEDT-TTF)2Hg(SCN)2Cl and κ-(BEDT-TTF)2Hg(SCN)2Br, both of which are more likely to be charge ordered than κ-(BEDT-TTF)2Cu2(CN)3. Then, the question of whether or not the NMR signature of κ-(BEDT-TTF)2Cu2(CN)3 is compatible with a spinon fermi surface and the nature of the "6 K anomaly" in κ-(BEDT-TTF)2Cu2(CN)3 is revisited via low temperature, high field NMR. In the case of κ-(BEDT-TTF)2Hg(SCN)2Cl, it is found that impurity spins dominate the low temperature NMR relaxation signature masking the intrinsic behavior. The 1/T1 relaxation of κ-(BEDT-TTF)2Hg(SCN)2Cl is very similar to that of κ-(BEDT-TTF)2Cu2(CN)3, and it is reasonable to believe the same "masking" may apply in the latter case. κ-(BEDT-TTF)2Hg(SCN)2Br, on the other hand, behaves quite differently from the other two. While none of the materials studied exhibit any signs of long range magnetic order, signatures for short range magnetic order were detected in κ-(BEDT-TTF)2Hg(SCN)2Br. κ-(BEDT-TTF)2Cu2(CN)3 is revisited at high fields in order to test the theory that impurity spins mask intrinsic relaxation behavior, as NMR signatures from impurities should be frozen out at sufficiently high fields. The relaxation signature of κ-(BEDT-TTF)2Cu2(CN)3 is found to be gapped, inconsistent with a spinon fermi surface. The nature of this gap remains unclear. Some exploration into the Inverse Laplace Transform (ILT) method as a tool for analyzing the stretched exponential in the context of κ-(BEDT-TTF)2Cu2(CN)3 is discussed as well.
■590 ▼aSchool code: 0031.
■650 4▼aCondensed matter physics.
■650 4▼aApplied physics.
■650 4▼aTheoretical physics.
■653 ▼aFrustrated magnets
■653 ▼aNuclear magnetic resonance
■653 ▼aQuantum spin liquids
■653 ▼aSuperconductivity
■653 ▼aSpinon fermi surface
■690 ▼a0611
■690 ▼a0753
■690 ▼a0215
■71020▼aUniversity of California, Los Angeles▼bPhysics 0666.
■7730 ▼tDissertations Abstracts International▼g84-12B.
■773 ▼tDissertation Abstract International
■790 ▼a0031
■791 ▼aPh.D.
■792 ▼a2023
■793 ▼aEnglish
■85640▼uhttp://www.riss.kr/pdu/ddodLink.do?id=T16933377▼nKERIS▼z이 자료의 원문은 한국교육학술정보원에서 제공합니다.
■980 ▼a202402▼f2024
