Quantum Phase Transitions in Condensed Matter and Atomic Physics

该基金支持基于量子相变研究的基础凝聚态物理理论研究。还包括原子物理和凝聚态物理之间的联系的研究；特别是对捕获的超冷原子系统的研究。量子相变是物质在绝对零度温度下的状态变化，由载流子浓度、磁场强度或压力等调谐参数的变化驱动。在传统相之间的量子临界点附近的低温下对材料的研究已被证明是寻找具有新物理性质的新量子相的沃土。将对金属间化合物和被捕获的原子气体进行一些研究，分析由于最近实验技术的进步而可以获得的许多量子相和转变中的一些。对于铜超导体，将对PI最近在1/8载流子掺杂附近的超流体-绝缘体跃迁理论进行扩展，以便对高精度扫描隧道显微镜和中子散射实验进行具体预测。该理论的一个核心成分是超导体漩涡所扮演的新角色，它的行为就像在磁场中运动的量子粒子。还将研究莫特绝缘体的密度波阶与节点准粒子之间的相互作用，目的是获得热输运实验的预测。还将研究金属间重费米子化合物中的磁相变，探索在量子临界点处出现的定义分数化激发。对于捕获的超冷原子系统，描述了新的量子临界点，可以在光学晶格和费什巴赫共振附近进行实验探索。这些实验的详细理论将得到发展。PI编写了一本影响深远且广泛使用的教科书《量子相变》，这是平装本的第二次印刷。PI正在编写第二版，它将纳入这项研究的想法，并增加章节以使更广泛的可访问性。PI还为各种各样的听众就这项研究发表了讲座和文章。这将继续下去。各级学生都将参与这项研究。这个项目涉及凝聚态物理的理论研究及其与原子物理的联系。这个项目是基于量子相变的。这些相变（想象水变成冰）发生在绝对零度，量子效应占主导地位。这些相变通常会导致物质的新状态。这些研究是现代凝聚态物理基本核心领域的一部分，但有朝一日可能会找到技术应用。PI编写了一本影响深远且广泛使用的教科书《量子相变》，这是平装本的第二次印刷。PI正在编写第二版，它将纳入这项研究的想法，并增加章节以使更广泛的可访问性。PI还为各种各样的听众就这项研究发表了讲座和文章。这将继续下去。各级学生都将参与这项研究

This grant supports theoretical research on fundamental condensed matter physics based on the study of quantum phase transitions. Also included are studies of the connections between atomic physics and condensed matter physics; in particular studies of systems of trapped ultracold atoms.Quantum phase transitions are changes in state of matter at the absolute zero of temperature, driven by changes in a tuning parameter such as carrier concentration, magnetic field strength, or pressure. Studies of materials at low temperatures in the vicinity of quantum critical points between conventional phases have proven to be fertile ground for finding new quantum phases with novel physical properties. A number of studies will be undertaken of intermetallic compounds and trapped atomic gases analyzing some of the many quantum phases and transitions that have become accessible by recent advances in experimental technologies. For the cuprate superconductors, extensions of the PI's recent theory for the superfluid-insulator transition in the vicinity of 1/8 carrier doping will be made, to allow specific predictions for high precision scanning tunneling microscopy and neutron scattering experiments. A central ingredient of the theory is the novel role played by the vortices of the superconductor, which behave like quantum particles moving in a magnetic field. Also to be studied is the interplay between the density wave order of the proximate Mott insulator and the nodal quasiparticles with the aim of obtaining predictions for thermal transport experiments. Also to be studied are magnetic phase transitions in the intermetallic heavy fermion compounds, exploring the emergence of deconfined fractionalized excitations at the quantum critical point. For the trapped ultracold atomic systems, new quantum critical points have been described that can be explored experimentally on optical lattices and near a Feshbach resonance. Detailed theories of these experiments will be developed.The PI has written a seminal and widely used textbook, Quantum Phase Transitions, that is in its second printing as a paperback. The PI is working on a second edition that will incorporate ideas from this research, and adding sections to enable wider accessibility. The PI has also presented lectures and written articles on this research for a wide variety of audiences. This will continue. Students at all levels will be involved with this research.%%% This project involves theoretical studies of condensed matter physics and its connections to atomic physics. The project is based on quantum phase transitions. These are phase transitions (think of water turning to ice) that occur at absolute zero of temperature where quantum effects dominate. These phase transitions often lead to new and novel states of matter. These studies are part of the fundamental core area of modern condensed matter physics, and yet may someday find technological applications. The PI has written a seminal and widely used textbook, Quantum Phase Transitions, that is in its second printing as a paperback. The PI is working on a second edition that will incorporate ideas from this research, and adding sections to enable wider accessibility. The PI has also presented lectures and written articles on this research for a wide variety of audiences. This will continue. Students at all levels will be involved with this research.***