学术活动
量子材料
One-Dimensional Luttinger Liquids in a Two-Dimensional Moiré Lattice
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主讲人: Pengjie Wang (Princeton University)
地点: 腾讯会议 ID:890 481 046
时间: 2021年11月3日 (周三)下午3:00
主持 联系人: 林熙<xilin@pku.edu.cn>
主讲人简介: Pengjie Wang is a postdoctoral researcher working with Prof. Sanfeng Wu, in the Department of Physics, Princeton University. He earned his PhD under the supervision of Prof. Xi Lin in 2018, in the International Center for Quantum Materials, Peking University. His current research interests focus on the interplay of strong correlations and topology in 2D crystals and twisted stacks.

摘要:

The Luttinger liquid (LL) model of one-dimensional (1D) electronic systems provides a powerful tool for understanding strongly correlated physics including the quasi-particle excitations, e.g., spin-charge separation. Substantial theoretical efforts have attempted to extend the LL phenomenology to two dimensions (2D), especially in models of closely packed perfect arrays of 1D quantum wires, each being described as a LL. For instance, such coupled-wire models have been successfully used to construct 2D anisotropic non-Fermi liquids, various quantum Hall states, topological phases, and quantum spin liquids. Despite these exciting theoretical developments, an experimental demonstration of high-quality arrays of 1D LLs suitable for realizing these models remains absent. In this talk, I will mainly present our recent experimental realization of 2D arrays of 1D LLs in a moiré superlattice made of twisted bilayer tungsten ditelluride (tWTe2). Originating from the anisotropic lattice of the monolayer, the moiré pattern of tWTe2 hosts identical, parallel 1D electronic channels, separated by a fixed nanoscale distance, which is tunable by the twist angle between layers. At a twist angle of ~ 5 degrees, we find that hole-doped tWTe2 exhibits exceptionally large transport anisotropy with a resistance ratio of ~ 1000. The conductance measurement reveals a power-law scaling behavior, consistent with the formation of a 2D anisotropic phase that resembles an array of LLs. Our results open the door for realizing a variety of 2D correlated and topological quantum phases based on coupled-wire models and LL physics.