Classification and Characterization of Crystalline Topological Invariants in Quantum Many-Body States- [electronic resource]
Classification and Characterization of Crystalline Topological Invariants in Quantum Many-Body States- [electronic resource]
- 자료유형
- 학위논문파일 국외
- 최종처리일시
- 20240214101158
- ISBN
- 9798380579391
- DDC
- 530
- 서명/저자
- Classification and Characterization of Crystalline Topological Invariants in Quantum Many-Body States - [electronic resource]
- 발행사항
- [S.l.]: : University of Maryland, College Park., 2023
- 발행사항
- Ann Arbor : : ProQuest Dissertations & Theses,, 2023
- 형태사항
- 1 online resource(342 p.)
- 주기사항
- Source: Dissertations Abstracts International, Volume: 85-04, Section: B.
- 주기사항
- Advisor: Barkeshli, Maissam.
- 학위논문주기
- Thesis (Ph.D.)--University of Maryland, College Park, 2023.
- 사용제한주기
- This item must not be sold to any third party vendors.
- 초록/해제
- 요약The theory of topological phases of matter, now a major direction in condensed matter physics, is framed around two complementary problems. The first is to mathematically classify topological states of matter given various symmetries, in terms of suitable topological invariants. The second is to characterize a given state by numerically or experimentally extracting the topological invariants associated with it. Although remarkable progress has been made for topological states with internal symmetries, major open questions remain in the case of many-body systems with crystalline symmetries, especially those with a nonzero Chern number and a magnetic field.The first part of this thesis develops a theory of crystalline topological response in (2+1) dimensions based on the idea of crystalline gauge fields and their effective actions, which we derive using topological quantum field theory. We use this to obtain a complete classification of topological states with U(1) charge conservation, discrete magnetic translation, and point group rotation symmetries, finding several new invariants. We separately consider symmetry-enriched topological states of bosons, which admit anyonic excitations with fractional statistics, and invertible fermionic states, which do not.The second part of this thesis focusses on numerically extracting these invariants from many-body invertible states. First we study two quantized invariants, the discrete shift, and a charge polarization which is quantized by rotational symmetries. We show how to extract these invariants in multiple different ways, which include the fractional charge bound to lattice defects, as well as the angular and linear momentum of magnetic flux. Thereafter, we obtain a complete characterization of the theoretically predicted invariants, by studying the expectation value of the ground state under partial rotation operators.An immediate application of these ideas is to fully characterize the celebrated Hofstadter model of spinless free fermions on a square lattice. Although the Chern number and filling were first computed in this model in 1982, our theory predicts seven nontrivial invariants, including four new invariants which depend on the crystalline symmetry. We compute these numerically and obtain several additional colorings of Hofstadter's butterfly.
- 일반주제명
- Theoretical physics.
- 일반주제명
- Quantum physics.
- 기타저자
- University of Maryland, College Park Physics
- 기본자료저록
- Dissertations Abstracts International. 85-04B.
- 기본자료저록
- Dissertation Abstract International
- 전자적 위치 및 접속
- 로그인 후 원문을 볼 수 있습니다.