Dynamics, Thermodynamics and Spin Transport in Random Quantum Spin Chains

9971541 杨 该奖项由许多理论项目组成，旨在提高我们对各种随机量子磁系统，特别是随机自旋链的长距离，低能量特性的理解。这些理论研究的动机来自于对这些类型系统的广泛实验活动，以及对理解具有强相互作用/关联和强无序的量子多体系统物理的普遍兴趣。一般来说，多体系统中的强相互作用和无序不能用标准微扰理论来处理，特别是当系统的维数很低时。随机量子自旋链是这种系统的典型例子。利用量子自旋链的一维性质，近年来发展了强有力的非微扰理论工具来研究量子自旋链。这些工具包括映射到有效量子场论、玻色化、真实的空间重整化群等，在这里研究的项目中，人们使用和扩展这些工具来揭示关于这些系统的物理性质的重要新信息，包括：由随机自旋链支撑的各种稳定相的自旋动力学和输运性质;在更一般的耦合作用下，随机量子自旋链中是否存在新的稳定相，（除了迄今为止研究的那些）之间的自旋是允许的;链之间的横向耦合对物理性质的影响;由系统中动力学自由度产生的无序效应等。此外，我们亦会尝试发展新的理论工具来研究这些系统，例如利用场论以一些新的非定域序参数来描述自旋链。这些计划的进展，不但会加深我们对各种随机量子系统物理的理解，也揭示了一般强相互作用多体系统的性质。该奖项由许多理论项目组成，旨在提高我们对各种随机量子磁系统，特别是随机自旋链的长距离，低能量特性的理解。这些理论研究的动机来自于对这些类型系统的广泛实验活动，以及对理解具有强相互作用/关联和强无序的量子多体系统物理的普遍兴趣。这些项目的进展不仅有望加深我们对各种随机量子系统物理的理解，也揭示了一般强相互作用多体系统的性质。*

9971541 Yang This award is comprised of a number of theoretical projects that are aimed at enhancing our understanding of the long-distance, low-energy properties of various random quantum magnetic systems, especially random spin chains. The motivation for these theoretical studies comes from both the extensive experimental activity with these types of systems, and the general interest in understanding the physics of quantum many-body systems with strong interaction/correlation and strong disorder.In general, strong interaction and disorder in many-body systems cannot be treated using standard perturbation theory, especially when the dimensionality of the system is low. Random quantum spin chains are typical examples of such systems. Powerful nonperturbative theoretical tools have been developed recently to study quantum spin chains, taking advantage of their one-dimensional nature. These tools include mapping onto effective quantum field theories, bosonization, real space renormalization group, etc.In the projects studied here, one uses and extends these tools to uncover important new information about the physical properties of these systems, including: the spin dynamics and transport properties of various stable phases supported by random spin chains; whether there exist new stable phases in random quantum spin chains that have not been studied before, when more general couplings (other than those studied thus far) among spins are allowed; the effects of transverse couplings between the chains on the physical properties; the effects of disorder generated by dynamical degrees of freedom in the system, etc. Attempts will also be made to develop new theoretical tools to study these systems, such as describing spin chains using field theories in terms of some novel non-local order parameters.Progress made on these projects is expected not only to deepen our understandings of the physics of various random quantum systems, but also to shed light on the properties of strongly interacting many-body systems in general. %%%This award is comprised of a number of theoretical projects that are aimed at enhancing our understanding of the long-distance, low-energy properties of various random quantum magnetic systems, especially random spin chains. The motivation for these theoretical studies comes from both the extensive experimental activity with these types of systems, and the general interest in understanding the physics of quantum many-body systems with strong interaction/correlation and strong disorder.Progress made on these projects is expected not only to deepen our understandings of the physics of various random quantum systems, but also to shed light on the properties of strongly interacting many-body systems in general.***