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A Quantum-Classical Study of Monolayer Transition Metal Dichalcogenides
A Quantum-Classical Study of Monolayer Transition Metal Dichalcogenides
상세정보
- 자료유형
- 학위논문 서양
- 최종처리일시
- 20260202105300
- ISBN
- 9798265483072
- DDC
- 540
- 서명/저자
- A Quantum-Classical Study of Monolayer Transition Metal Dichalcogenides
- 발행사항
- [Sl] : Northwestern University, 2025
- 발행사항
- Ann Arbor : ProQuest Dissertations & Theses, 2025
- 형태사항
- 224 p
- 주기사항
- Source: Dissertations Abstracts International, Volume: 87-06, Section: B.
- 주기사항
- Advisor: Tempelaar, Roel.
- 학위논문주기
- Thesis (Ph.D.)--Northwestern University, 2025.
- 초록/해제
- 요약Monolayer transition metal dichalcogenides (TMDs) are a transformative class of 2D material. Their incorporation into valleytronic devices promises faster operating speeds and lower power consumption by leveraging spin-valley polarized excitons for information storage and processing. The realization of such devices, however, is fundamentally hindered by exciton depolarization, which causes a loss of valley information on a timescale too short for practical device operation. Disentangling the microscopic origins of rapid depolarization could lead to new experimental routes for overcoming it, paving the way for new kinds of TMD-based devices. The convolution of different depolarization pathways, however, has made experimentally isolating them difficult, if not impossible. Instead, a theoretical approach that provides a microscopic description of the exciton dynamics could identify the dominant contributions to depolarization and motivate strategies to overcome them. Quantum-classical (QC) methods are a promising approach in this regard. They treat electronic motion quantum-mechanically and retain explicit nuclear motion through an inexpensive classical description that retains microscopic detail. This endows them with a favorable cost-accuracy trade-off that has made them popular for studying excited state dynamics in molecular systems. The practical application of QC methods to materials, however, is hindered by their real-space formulation, which becomes prohibitively expensive for the system sizes required to converge material properties. In this thesis, I develop reciprocal-space QC methods that can be combined with Brillouin zone truncation to efficiently simulate periodic materials at reduced cost. I apply this approach to investigate the microscopic origins of rapid depolarization in monolayer TMDs, revealing the role of an exciton-phonon resonance in the depolarization dynamics of MoS2. I then deliver these and other capabilities to the wider research community through the development of a versatile open-source software package: QC Lab.
- 일반주제명
- Chemistry
- 일반주제명
- Physical chemistry
- 일반주제명
- Materials science
- 키워드
- Exciton
- 키워드
- Mean field
- 키워드
- Surface hopping
- 기타저자
- Northwestern University Chemistry
- 기본자료저록
- Dissertations Abstracts International. 87-06B.
- 전자적 위치 및 접속
- 로그인 후 원문을 볼 수 있습니다.
MARC
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■00520260202105300
■006m o d
■007cr#unu||||||||
■020 ▼a9798265483072
■035 ▼a(MiAaPQ)AAI32281394
■040 ▼aMiAaPQ▼cMiAaPQ
■0820 ▼a540
■1001 ▼aAndreas Krotz, Alex.
■24512▼aA Quantum-Classical Study of Monolayer Transition Metal Dichalcogenides
■260 ▼a[Sl]▼bNorthwestern University▼c2025
■260 1▼aAnn Arbor▼bProQuest Dissertations & Theses▼c2025
■300 ▼a224 p
■500 ▼aSource: Dissertations Abstracts International, Volume: 87-06, Section: B.
■500 ▼aAdvisor: Tempelaar, Roel.
■5021 ▼aThesis (Ph.D.)--Northwestern University, 2025.
■520 ▼aMonolayer transition metal dichalcogenides (TMDs) are a transformative class of 2D material. Their incorporation into valleytronic devices promises faster operating speeds and lower power consumption by leveraging spin-valley polarized excitons for information storage and processing. The realization of such devices, however, is fundamentally hindered by exciton depolarization, which causes a loss of valley information on a timescale too short for practical device operation. Disentangling the microscopic origins of rapid depolarization could lead to new experimental routes for overcoming it, paving the way for new kinds of TMD-based devices. The convolution of different depolarization pathways, however, has made experimentally isolating them difficult, if not impossible. Instead, a theoretical approach that provides a microscopic description of the exciton dynamics could identify the dominant contributions to depolarization and motivate strategies to overcome them. Quantum-classical (QC) methods are a promising approach in this regard. They treat electronic motion quantum-mechanically and retain explicit nuclear motion through an inexpensive classical description that retains microscopic detail. This endows them with a favorable cost-accuracy trade-off that has made them popular for studying excited state dynamics in molecular systems. The practical application of QC methods to materials, however, is hindered by their real-space formulation, which becomes prohibitively expensive for the system sizes required to converge material properties. In this thesis, I develop reciprocal-space QC methods that can be combined with Brillouin zone truncation to efficiently simulate periodic materials at reduced cost. I apply this approach to investigate the microscopic origins of rapid depolarization in monolayer TMDs, revealing the role of an exciton-phonon resonance in the depolarization dynamics of MoS2. I then deliver these and other capabilities to the wider research community through the development of a versatile open-source software package: QC Lab.
■590 ▼aSchool code: 0163.
■650 4▼aChemistry
■650 4▼aPhysical chemistry
■650 4▼aMaterials science
■653 ▼aExciton
■653 ▼aMean field
■653 ▼aSurface hopping
■653 ▼aTransition metal dichalcogenides
■653 ▼aValley depolarization
■690 ▼a0485
■690 ▼a0494
■690 ▼a0794
■71020▼aNorthwestern University▼bChemistry.
■7730 ▼tDissertations Abstracts International▼g87-06B.
■790 ▼a0163
■791 ▼aPh.D.
■792 ▼a2025
■793 ▼aEnglish
■85640▼uhttp://www.riss.kr/pdu/ddodLink.do?id=T17360080▼nKERIS▼z이 자료의 원문은 한국교육학술정보원에서 제공합니다.
