Microscopic Theory of Quantum Fluids and Nuclear Systems

PHY-0140316 Clark该奖项支持对量子多体问题的广泛研究。主要目标是预测，从第一原理，强相关系统的基本和技术的重要性，假设现实的相互作用和dealingwith现实的条件下的密度和温度的属性。 主要集中在原子核和核物质理论中的突出问题。 然而，这项研究也跨越学科界限，进入中子星物质、氦和其他量子液体、强关联电子系统、自旋晶格模型和晶格规范系统中的多体问题。 大部分的工作涉及应用两个高度发达的半解析方法，即自洽的绿色函数的方法和相关的基础理论。 除了它们的定量准确性和从头算特性，这些方法能够提供与量子相干性相关的重要系统特性的信息，这些信息还不能通过蛮力计算机模拟获得。 当前和持久的兴趣的两个主题将在补助金期间强调，即短期和长期相关性在核系统中的对比作用，以及在各种物理环境中发生量子相变。 在后一个主题中，配对现象正在用新技术进行研究，这些技术有望对中子星，奇异核和液态氦-3的超流性以及高温超导性有独特的见解。 选择问题和目标的动机是撞击设施的潜力和轨道观测台对紧凑天体物理物体的观测。 该项目的具体重点包括：（一）比较核物质和有限核中的π介子长程激发，以确定在计算核饱和性质时是否应排除这种相关性;（二）改进对氧-16集体特征的描述，以便能够定量评估单核子剔除的光谱因素和双核子去除的截面;（iii）分析实验数据以推断原子核中最高动量质子的性质（“最后失踪的质子”），（iv）在配对理论中应用新的分析和计算方法来阐明中子物质，对称核物质，液态氦-3和量子色动力学的超流体相图，（v）探索费米液体理论的崩溃，表现在费米子凝聚和其他重排的单粒子自由度在强关联系统，和（vi）调查的数学和多体方面的量子控制有关的激光控制的化学反应和量子计算。 延续悠久的传统，研究生在教学和研究的生产性职业生涯的准备在该计划中发挥着核心作用，对其成功至关重要。

PHY-0140316ClarkThis award supports research on a broad spectrum of quantum many-body problems. The primary objective is prediction, from first principles,of the properties of strongly correlated systems of fundamental and technological importance, assuming realistic interactions and dealingwith realistic conditions of density and temperature. The main focus is on outstanding questions in the theory of nuclei and nuclear matter. However, the research also crosses disciplinary boundaries into many-body problems in neutron-star matter, helium and other quantum liquids, strongly correlated electron systems, spin-lattice models, and lattice-gauge systems. Much of the work involves application of two highly developed semi-analytic methods, namely the self-consistent Green's function approach and correlated-basis theory. In addition to their quantitative accuracy and ab initio character, these methods are capable of providing information on important system properties associated with quantum coherence that are not yet accessible to brute-force computer simulation. Two themes of current and enduring interest will be emphasized during the period of the grant, namely the contrasting roles of short- and long-range correlations in nuclear systems and the occurrence of quantum phase transitions in a rich variety of physical settings. Within the latter theme, pairing phenomena are being studied with new techniques that promise unique insights into superfluidity in neutron stars, exotic nuclei, and liquid Helium-3 as well as high-temperature superconductivity. The selection of problems and goals is motivated by the potential for impact facilities and observations of compact astrophysical objects from orbiting observatories. Specific highlights of the project include (i) a comparison of pionic long-range excitations in nuclear matter and in finite nuclei to determine whether such correlations should be excluded in the calculation of nuclear saturation properties, (ii) an improved description of collective features of Oxygen-16 that will permit quantitative evaluation of spectroscopic factors for single-nucleon knockout and cross sections for two-nucleon removal, (iii) analysis ofexperimental data to deduce the properties of the highest-momentum protons in the nucleus (the "last missing protons"), (iv) application of incisive new methods of analysis and computation in pairing theoryto elucidate the superfluid phase diagrams of neutron matter, symmetrical nuclear matter, liquid Helium-3, and quantum chromodynamics, (v)exploration of the breakdown of Fermi-liquid theory, as manifested in fermion condensation and other rearrangements of single-particle degrees of freedom in strongly correlated systems, and (vi) investigation of mathematical and many-body aspects of quantum control relevant to laser control of chemical reactions and to quantum computation. Continuing a long tradition, the preparation of graduate students for productive careers in teaching and research plays a central role in the program, essential to its success.