分数量子霍尔液体中的几何自由度及类引力子元激发  

Geometric degrees of freedom and graviton-like excitations in fractional quantum Hall liquids

作　　者：杨昆[1] Kun Yang(Department of Physics,Florida State University,Tallahassee Florida 32306,USA)

机构地区：[1]佛罗里达州立大学物理系,美国佛罗里达塔拉哈西32306

出　　处：《物理学报》2024年第17期28-32,共5页Acta Physica Sinica

基　　金：美国国家科学基金会(批准号:DMR-2315954,DMR-2128556);佛罗里达州资助的课题.

摘　　要：拓扑在凝聚态物理中的应用始于量子霍尔效应的研究,并逐渐成为现代凝聚态物理的主旋律.其重要性在于它描述物理系统的普适性质.但基于拓扑场论的分数量子霍尔液体宏观描述并非完备.本文从微观角度出发讨论分数量子霍尔液体中的几何自由度及其量子动力学,揭示其基本元激发为自旋为2的类引力子并据有特定手性,着重讨论该手征类引力子的实验探测.The application of topology in condensed matter physics began with the study of the quantum Hall effect and has gradually become the main theme of modern condensed matter physics.Its importance lies in capturing the universal properties of physical systems.In particular,fractional quantum Hall liquids are the most strongly correlated systems and exhibit topological order.Its most important and universal feature is the quasiparticle(quasi-hole)elementary excitations with fractional charge and statistics,which are captured by topological field theories.However,such a macroscopic description of fractional quantum Hall liquids is not complete,because it misses an important geometric aspect that is important for both universal and non-universal properties of the system.In particular,the nature of its electrically neutral elementary excitations has not been fully understood until recently.Finite-wavelength electrically neutral elementary excitations can be viewed as charge density waves or bound states of quasi-particles-quasi-holes.However,such pictures are not applicable in the long-wave limit,so a new theoretical framework is needed.In this theoretical framework,one of the most basic degrees of freedom is the metric tensor that describes the electron correlation.Figuratively speaking,it describes the geometric shape of the correlation hole around the electron.Therefore,this theory is called the geometric theory of the fractional quantum Hall effect.Since the metric tensor is also the basic degree of freedom of the theory of gravity,this theoretical framework can be regarded as a certain type of quantum theory of gravity.Its basic elementary excitation is a spin-two graviton.This perspective discusses the geometric degrees of freedom and its quantum dynamics in quantum Hall liquids from a microscopic perspective,revealing that its basic elementary excitations are spin-two graviton-like particles with specific chirality,and focuses on the experimental detection of this chiral graviton-like particle.The figure illustra

关 键 词：拓扑 几何 引力子 强关联 

分 类 号：O469[理学—凝聚态物理]