자료유형 | 학위논문 |
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서명/저자사항 | Berry Phase in Composite Fermi Liquids. |
개인저자 | Wang, Jie. |
단체저자명 | Princeton University. Physics. |
발행사항 | [S.l.]: Princeton University., 2019. |
발행사항 | Ann Arbor: ProQuest Dissertations & Theses, 2019. |
형태사항 | 128 p. |
기본자료 저록 | Dissertations Abstracts International 80-12B. Dissertation Abstract International |
ISBN | 9781392271704 |
학위논문주기 | Thesis (Ph.D.)--Princeton University, 2019. |
일반주기 |
Source: Dissertations Abstracts International, Volume: 80-12, Section: B.
Publisher info.: Dissertation/Thesis. Advisor: Haldane, Duncan. |
이용제한사항 | This item must not be sold to any third party vendors. |
요약 | Two-dimensional electron gas in high magnetic field exhibits a wide variety of interesting physical properties. Perhaps most notable of these is the quantum Hall effect, which is a classic example of a topological phase. Another interesting phase occurs at even denominator filling fraction is the so-called "composite Fermi liquid". Such compressible phase is traditionally thought of as a Fermi liquid of "composite fermions" due to B. I. Halperin, P. A. Lee and N. Read (HLR).Composite Fermi liquid has gained renewed interest recently due to the particle-hole symmetry and Berry phase: when the lowest Landau level is half filled, the effective Hamiltonian is particle-hole symmetric. However, it is unclear how the HLR description realizes this symmetry. A key ingredient that was missing in HLR's treatment seems to be a PI Fermi sea Berry phase associated with transporting a composite fermion around the Fermi surface. Motivated by the symmetry and Berry phase, recently D. T. Son conjectured that composite fermions are relativistic Dirac particles. In Son's theory, particle-hole symmetry acts in a way akin to time reversal on Dirac fermions, and the PI Berry phase is a curvature singularity at Dirac node.A direct measurement of this PI Berry phase is one of the main results in this dissertation. We examined a model wavefunction that explicitly exhibits a Fermi surface, and has been shown to give good agreement with states found in exact diagonalization studies. We then formulated a many-body version of Berry phase for transporting a single composite fermion around a path in momentum space, and evaluated the Berry phase. To study the property of model wavefunction and Berry phase on larger system sizes, we developed "lattice Monte Carlo" technique based on a mathematically exact discretized formulation of holomorphic quantum Hall states on torus. Besides half filling, the Berry phase at 1/4 was found to be remarkably interesting: it suggests the emergence of Dirac fermion at generic filling fraction. Motived by this, an effective theory, dubbed as "flux attached Dirac fermion theory", which generalizes Son's theory and covers all filling fractions was proposed. |
일반주제명 | Quantum physics. Condensed matter physics. |
언어 | 영어 |
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