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Study of Electrical, Magnetic, and Thermal Properties in Kagome Materials
Study of Electrical, Magnetic, and Thermal Properties in Kagome Materials
상세정보
- 자료유형
- 학위논문 서양
- 최종처리일시
- 20260202105240
- ISBN
- 9798291569214
- DDC
- 530
- 저자명
- Zheng, Guoxin.
- 서명/저자
- Study of Electrical, Magnetic, and Thermal Properties in Kagome Materials
- 발행사항
- [Sl] : University of Michigan, 2025
- 발행사항
- Ann Arbor : ProQuest Dissertations & Theses, 2025
- 형태사항
- 211 p
- 주기사항
- Source: Dissertations Abstracts International, Volume: 87-03, Section: B.
- 주기사항
- Advisor: Li, Lu.
- 학위논문주기
- Thesis (Ph.D.)--University of Michigan, 2025.
- 초록/해제
- 요약The search and study of quantum materials are always exciting within the condensed matter community. One particularly intriguing group of quantum materials is based on the "kagome lattice" which consists of a two-dimensional pattern of corner-sharing triangles. The unique feature of the kagome lattice is that the tight binding model yields an electronic structure hosting Dirac nodes, van Hove singularities, and flat bands, providing an excellent platform for studying phenomena such as charge density waves, superconductivity, and non-trivial topology. Another remarkable property of kagome lattice is the high degree of geometrical frustration it introduces, which makes it a promising structure to realize quantum spin liquids (QSLs). In this study, I primarily focused on two classes of kagome materials: kagome metals and kagome insulators.Firstly, to detect subtle but crucial features like quantum oscillations in the thermal Hall effect, we designed a sensitive differential amplifier to measure the resistance difference between two thermometers, achieving a resolution of 0.05 mK at a bath temperature of 1 K. This advancement enabled us to clearly resolve quantum oscillations in the thermal Hall channel in CsV3Sb5. Additionally, to probe the magnetic properties of quantum materials with rapid dynamic responses, we developed a MHz quartz-based magnetometry, which successfully captured quantum oscillations in bismuth within ultrafast pulsed magnetic fields.Secondly, to study the unique topological band structures of kagome lattice, westudied two kagome metals CsV3Sb5 and ScV6Sn6. In CsV3Sb5 we observed a large g-factor enhancement through quantum oscillations with the MHz Proximity-DetectorOscillator technique, which provides evidence for an exotic orbital-current state. In another kagome metal, ScV6Sn6, we mapped the Fermi surface through quantum oscillations measurements and identified a topologically nontrivial Dirac node near the Fermi surface via non-trivial Berry phase, which survived during the charge density wave transition.Thirdly, to study the strong frustrations and the corresponding potential QSL ground states in kagome lattice, we studied a newly discovered kagome Mott insulator YCu3(OH)6Br2[Brx(OH)1−x] (YCOB). Remarkably, we observe an unconventional one-ninth magnetization plateau under an applied magnetic field. Specific heat measurements indicate that this plateau corresponds to a gapless Dirac spin liquid state, and the evolution of the specific heat at higher fields suggests the emergence of a spinon Fermi surface. Moreover, following the plateau region, we detect magnetic oscillations through torque magnetometry, signaling the presence of charge-neutral spinon Fermi surfaces. This result is extraordinary because quantum oscillations are typically exclusive to metallic systems. Altogether, our observations suggest that YCOB hosts a field-induced Dirac spin liquid, positioning it as an exceptional platform for exploring the sought-after QSL state.
- 일반주제명
- Condensed matter physics
- 일반주제명
- Physics
- 일반주제명
- Quantum physics
- 키워드
- Kagome lattice
- 기타저자
- University of Michigan Physics
- 기본자료저록
- Dissertations Abstracts International. 87-03B.
- 전자적 위치 및 접속
- 로그인 후 원문을 볼 수 있습니다.
MARC
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■00520260202105240
■006m o d
■007cr#unu||||||||
■020 ▼a9798291569214
■035 ▼a(MiAaPQ)AAI32271996
■035 ▼a(MiAaPQ)umichrackham006305
■040 ▼aMiAaPQ▼cMiAaPQ
■0820 ▼a530
■1001 ▼aZheng, Guoxin.
■24510▼aStudy of Electrical, Magnetic, and Thermal Properties in Kagome Materials
■260 ▼a[Sl]▼bUniversity of Michigan▼c2025
■260 1▼aAnn Arbor▼bProQuest Dissertations & Theses▼c2025
■300 ▼a211 p
■500 ▼aSource: Dissertations Abstracts International, Volume: 87-03, Section: B.
■500 ▼aAdvisor: Li, Lu.
■5021 ▼aThesis (Ph.D.)--University of Michigan, 2025.
■520 ▼aThe search and study of quantum materials are always exciting within the condensed matter community. One particularly intriguing group of quantum materials is based on the "kagome lattice" which consists of a two-dimensional pattern of corner-sharing triangles. The unique feature of the kagome lattice is that the tight binding model yields an electronic structure hosting Dirac nodes, van Hove singularities, and flat bands, providing an excellent platform for studying phenomena such as charge density waves, superconductivity, and non-trivial topology. Another remarkable property of kagome lattice is the high degree of geometrical frustration it introduces, which makes it a promising structure to realize quantum spin liquids (QSLs). In this study, I primarily focused on two classes of kagome materials: kagome metals and kagome insulators.Firstly, to detect subtle but crucial features like quantum oscillations in the thermal Hall effect, we designed a sensitive differential amplifier to measure the resistance difference between two thermometers, achieving a resolution of 0.05 mK at a bath temperature of 1 K. This advancement enabled us to clearly resolve quantum oscillations in the thermal Hall channel in CsV3Sb5. Additionally, to probe the magnetic properties of quantum materials with rapid dynamic responses, we developed a MHz quartz-based magnetometry, which successfully captured quantum oscillations in bismuth within ultrafast pulsed magnetic fields.Secondly, to study the unique topological band structures of kagome lattice, westudied two kagome metals CsV3Sb5 and ScV6Sn6. In CsV3Sb5 we observed a large g-factor enhancement through quantum oscillations with the MHz Proximity-DetectorOscillator technique, which provides evidence for an exotic orbital-current state. In another kagome metal, ScV6Sn6, we mapped the Fermi surface through quantum oscillations measurements and identified a topologically nontrivial Dirac node near the Fermi surface via non-trivial Berry phase, which survived during the charge density wave transition.Thirdly, to study the strong frustrations and the corresponding potential QSL ground states in kagome lattice, we studied a newly discovered kagome Mott insulator YCu3(OH)6Br2[Brx(OH)1−x] (YCOB). Remarkably, we observe an unconventional one-ninth magnetization plateau under an applied magnetic field. Specific heat measurements indicate that this plateau corresponds to a gapless Dirac spin liquid state, and the evolution of the specific heat at higher fields suggests the emergence of a spinon Fermi surface. Moreover, following the plateau region, we detect magnetic oscillations through torque magnetometry, signaling the presence of charge-neutral spinon Fermi surfaces. This result is extraordinary because quantum oscillations are typically exclusive to metallic systems. Altogether, our observations suggest that YCOB hosts a field-induced Dirac spin liquid, positioning it as an exceptional platform for exploring the sought-after QSL state.
■590 ▼aSchool code: 0127.
■650 4▼aCondensed matter physics
■650 4▼aPhysics
■650 4▼aQuantum physics
■653 ▼aKagome lattice
■653 ▼aQuantum spin liquids
■653 ▼aTopological materials
■653 ▼aQuantum oscillations
■653 ▼aHigh magnetic fields
■690 ▼a0605
■690 ▼a0611
■690 ▼a0599
■71020▼aUniversity of Michigan▼bPhysics.
■7730 ▼tDissertations Abstracts International▼g87-03B.
■790 ▼a0127
■791 ▼aPh.D.
■792 ▼a2025
■793 ▼aEnglish
■85640▼uhttp://www.riss.kr/pdu/ddodLink.do?id=T17359952▼nKERIS▼z이 자료의 원문은 한국교육학술정보원에서 제공합니다.
