Quantum transport and hydrodynamics in strongly interacting systems: Symmetries, Quantum criticality and Entanglement

强相互作用系统中的量子输运和流体动力学：对称性、量子临界性和纠缠

• 批准号: RGPIN-2020-07070
• 负责人: Zhou, Fei
• 金额: $ 2.04万
• 依托单位: University of British Columbia
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2021
• 资助国家: 加拿大
• 起止时间: 2021-01-01 至 2022-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=741269
• 关键词: Quantum; transport; hydrodynamics; strongly; interacting

Over the last decade or so, there has been enormous growing interest from both theorists and various experimental physics communities in quantum dynamics in strongly interacting regimes. Impressive theoretical progress has been made on various research fronts. On the experimental side, the cutting edge pulsed-laser based pump-probe technique that many solid state labs are developing and perfecting is opening a door to more studies of quantum dynamics. Very recent observation of Planckian transport and scale invariant transport in strongly interacting materials further indicates universal transport phenomena in a broad class of very different interacting condensed matter states. The transport dynamics observed further suggest a possible intimate connection between the universal Planckian transport and fastest information spreading near a black hole. Hydrodynamics of Dirac fermions had also been observed in graphene and a few months ago, viscous flow due to mutual-interactions between Dirac fermions was imaged. These studies, theoretical and experimental ones, have revealed fascinating and unexpected aspects of dynamics.These intensive experimental efforts and impressive successes further demand new theoretical efforts on non-equilibrium quantum phenomena in strongly interacting regimes. In this proposal, we will research on quantum dynamics including transport dynamics and hydrodynamics in strongly interacting quantum critical regimes that are (nearly) scale invariant. We will explore universal transport dynamics and quantum hydrodynamics that can potentially and naturally emerge in these interacting systems. We will specially examine and identify new dimensions in parameter spaces where deviations from universal dynamics can be studied in a controllable and pronounced way. The main objective of is to test the robustness of potential universal dynamic phenomena against experimental variables and understand the resultant dynamics, transport and hydrodynamics in quantum critical regimes. To achieve these objectives, we divide the proposal into two parts, each of which emphasizes a few particular universal aspects of dynamic phenomena as outlined below. And these aspects will be examined in different condensed matter systems including cold gases, depending on which are experimentally more relevant and more practical to realize in labs. Part I addresses Planckian transport phenomena and hydrodynamics in strongly interacting Dirac fermions in 2D and 3D semi-metals near charge neutrality points. Dirac points can be considered to be critical ones and further strong interactions can result in Planckian transport and relativistic viscous hydrodynamic flow in ultra clean semi-metals where impurity and phonon scatterings are negligible. Part II concerns emergent universal conformal dynamics in strongly interacting cold gases and Fermi-Bose quantum mixtures near Feshbach resonance, as well as in interacting solid states near Lifshitz transitions.

在过去十年左右的时间里，理论家和各种实验物理界对强相互作用体系中的量子动力学产生了巨大的兴趣。在各个研究领域都取得了令人印象深刻的理论进展。在实验方面，许多固态实验室正在开发和完善基于脉冲激光的尖端泵浦探针技术，这为更多量子动力学研究打开了大门。最近对强相互作用材料中的普朗克输运和尺度不变输运的观察进一步表明，在一大类非常不同的相互作用的凝聚态物质状态中存在普遍的输运现象。观察到的传输动力学进一步表明普朗克传输与黑洞附近最快的信息传播之间可能存在密切联系。狄拉克费米子的流体动力学也在石墨烯中被观察到，几个月前，由于狄拉克费米子之间的相互作用而产生的粘性流被成像。这些理论和实验研究揭示了动力学的迷人和意想不到的方面。这些密集的实验努力和令人印象深刻的成功进一步要求对强相互作用体系中的非平衡量子现象进行新的理论努力。 在本提案中，我们将研究量子动力学，包括（几乎）尺度不变的强相互作用量子临界状态中的输运动力学和流体动力学。我们将探索在这些相互作用的系统中可能自然出现的通用输运动力学和量子流体动力学。我们将专门检查和识别参数空间中的新维度，在这些维度中，可以以可控且显着的方式研究与通用动力学的偏差。其主要目标是测试潜在的普遍动力学现象对实验变量的鲁棒性，并了解量子临界状态下所产生的动力学、输运和流体动力学。为了实现这些目标，我们将提案分为两个部分，每个部分都强调动态现象的一些特定的普遍方面，如下所述。这些方面将在包括冷气体在内的不同凝聚态物质系统中进行检查，具体取决于哪些系统在实验上更相关且在实验室中实现更实用。第一部分讨论电荷中性点附近 2D 和 3D 半金属中强相互作用狄拉克费米子的普朗克输运现象和流体动力学。狄拉克点可以被认为是关键点，进一步的强相互作用可以导致超洁净半金属中的普朗克输运和相对论粘性流体动力流动，其中杂质和声子散射可以忽略不计。第二部分涉及费什巴赫共振附近的强相互作用冷气体和费米-玻色量子混合物中以及在利夫希茨跃迁附近相互作用的固态中出现的普遍共形动力学。