Physical Properties of Strongly Correlated Quantum Liquids

强相关量子液体的物理性质

• 批准号: 0123156
• 负责人: Xiao-Gang Wen
• 金额: $ 21.3万
• 依托单位: Massachusetts Institute of Technology
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-11-01 至 2004-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0123156&HistoricalAwards=false
• 关键词: Physical; Properties; Strongly; Correlated; Quantum

This award supports theoretical research on strongly correlated electron systems, focusing on high temperature superconductors and quantum Hall systems. Research focuses on three areas: (1) The PI takes the view that underdoped high temperature superconductors have a non-fermi liquid metallic state that exhibits spin-charge separation. Research will focus on holon dynamics and the properties of a non-condensing quantum degenerate holon gas. The transition to the superconducting state will be studied with the aim of understanding how the superconducting transition is related to spin-charge recombination and how coherent quasiparticles can grow out of incoherent spinons and holons. The transition to the striped phase will also be studied; this is expected not to be a usual CDW transition. (2) The PI plans to develop a more complete theory of fractional quantum Hall states, with an aim to elucidate the mathematical structure of topological order. The chiral operator product algebra will be examined to see if it could form the basis of a general theory of topological order. It is expected that a deeper understanding of topological order will enable the calculation of the physical properties of non-Abelian fractional quantum Hall states and so enable their identification in experiments. (3) The PI plans to study continuous phase transitions between topological orders. Continuous phase transitions can occur between clean fractional quantum Hall states as long as these states contain neutral quasiparticles. The properties of the critical point depend on the topological orders of the two states involved and so, provide a useful way to study topological order experimentally. The PI plans to find general effective theories for continuous topological phase transitions and to understand the close relation between the topological order and the critical theory. The PI will also explore how neutral gapless excitations at the critical point interact with surface acoustic phonons and other experimental probes.%%%This award supports theoretical research on strongly correlated electron systems with a particular focus on high temperature superconductors and quantum Hall systems. The PI plans to use advanced theoretical methods to understand the nature of a proposed exotic metallic state of the high temperature superconductors and the nature of the phase transition from this state to the superconducting state. The metallic state is unlike that of an ordinary metal and the transition to superconductivity may differ qualitatively from that which occurs in well-understood superconductors. The PI will also study fractional quantum Hall states that exhibit internal order. A kind of continuous phase transition can occur between two such states with the same symmetry. The PI intends to develop a more comprehensive theory of these states and the phase transitions that can occur among them. This research contributes to fundamental understanding of strongly correlated electron materials.***

该奖项支持强关联电子系统的理论研究，重点是高温超导体和量子霍尔系统。研究集中在三个方面：(1)PI认为，欠掺杂高温超导体具有非费米液态金属状态，表现出自旋-电荷分离。研究将集中在Holon动力学和非凝聚量子简并Holon气体的性质上。向超导态的转变将被研究，目的是了解超导转变如何与自旋-电荷复合有关，以及相干准粒子如何从非相干自旋和合弄中生长出来。还将研究到条纹相的转变；预计这不是通常的CDW转变。(2)PI计划发展一个更完整的分数量子霍尔态理论，旨在阐明拓扑序的数学结构。我们将考察手征算子乘积代数，看它是否能构成拓扑序的一般理论的基础。对拓扑序的深入理解将有助于计算非阿贝尔分数量子霍尔态的物理性质，从而能够在实验中识别它们。(3)PI计划研究拓扑序之间的连续相变。清洁分数量子霍尔态之间可以发生连续相变，只要这些态包含中性准粒子。临界点的性质取决于所涉及的两个态的拓扑序，从而为实验研究拓扑序提供了一种有用的方法。PI计划为连续的拓扑相变找到普遍有效的理论，并理解拓扑序和临界理论之间的密切关系。PI还将探索临界点的中性无间隙激发如何与表面声学声子和其他实验探测器相互作用。%该奖项支持对强关联电子系统的理论研究，特别是高温超导体和量子霍尔系统。PI计划使用先进的理论方法来理解所提出的高温超导体的奇异金属状态的性质，以及从这种状态到超导状态的相变的性质。金属状态不同于普通金属，向超导性的转变可能与人们熟知的超导体中发生的转变有质的不同。PI还将研究表现出内部有序的分数量子霍尔态。在具有相同对称性的两个这样的状态之间可以发生一种连续的相变。PI打算对这些状态以及它们之间可能发生的相变发展一个更全面的理论。这项研究有助于对强关联电子材料的基本理解。