자료유형 | 학위논문 |
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서명/저자사항 | Imaging Quantum Hall Wavefunctions with a Scanning Tunneling Microscope: From Spontaneous Symmetry Breaking to Interacting Domain Boundary Modes. |
개인저자 | Randeria, Mallika. |
단체저자명 | Princeton University. Physics. |
발행사항 | [S.l.]: Princeton University., 2019. |
발행사항 | Ann Arbor: ProQuest Dissertations & Theses, 2019. |
형태사항 | 176 p. |
기본자료 저록 | Dissertations Abstracts International 81-04B. Dissertation Abstract International |
ISBN | 9781085649797 |
학위논문주기 | Thesis (Ph.D.)--Princeton University, 2019. |
일반주기 |
Source: Dissertations Abstracts International, Volume: 81-04, Section: B.
Advisor: Yazdani, Ali. |
이용제한사항 | This item must not be sold to any third party vendors. |
요약 | Quantum materials provide a rich platform for realizing emergent phenomena, where interactions between electrons lead to properties that are strikingly different from those of individual electrons. Confining electrons to two dimensions and subjecting them to large magnetic fields enhances the effects of Coulomb interactions, which can manifest as a spontaneous lifting of spin, valley or other degeneracies in these quantum Hall systems. Experiments on a number of materials have primarily relied on global measurement techniques to explore this phase space, but locally imaging these broken-symmetry states has remained a challenge. With the useof a scanning tunneling microscope (STM), we directly visualize quantum Hall wavefunctions on the surface of a bismuth crystal, which enables us to probe the spatial signatures of spontaneous valley ordering. We identify the emergence of a nematic electronic phase, which breaks the rotational symmetry of the underlying crystal lattice, and a ferroelectric phase that carries an in-plane electric dipolemoment. Furthermore, we use the STM to investigate one-dimensional channels that form at the boundary between different valley-polarized quantum Hall states. We find markedly different regimes where these channels are either metallic or insulating, depending on constraints imposed on electron-electron interactions by the valley flavor. These experiments set the stage visualizing fractional quasiparticles in quantum Hall systems, and more generally for using local imaging techniques in future explorations of novel interaction-driven phenomena. |
일반주제명 | Condensed matter physics. Quantum physics. Low temperature physics. |
언어 | 영어 |
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