Search for novel collective phenomena due to many-body correlations in low dimensional systems

寻找低维系统中多体相关性引起的新集体现象

• 批准号: RGPIN-2019-05486
• 负责人: Maiti, Saurabh
• 金额: $ 1.75万
• 依托单位: Concordia University
• 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=738326
• 关键词: Search; novel; collective; phenomena; due

Low dimensional systems are interesting class of systems exhibiting novel quantum phenomena. Some examples that has created a lot of buzz are unconventional superconductors and Graphene-based materials. They offer great promise for the future by aiding in discovery on novel quantum phases (involving magnetism, density waves, superconductivity and even coexistence amongst them); and replacing electronics with Spintronics: a more efficient means to transfer information. Another unavoidable ingredient in low dimensional systems is the spin-orbit coupling that breaks parity. When combined with superconductivity it can lead to exotic excitations like Majorana fermions which are essential for quantum computing. However, much of the excitement has been at the level of single-particle physics. This does not allow us to exploit the benefits of the quantum world to the fullest potential. To do that one needs to understand the role of many-body correlations in such systems. This research program is designed to achieve precisely that in a very systematic manner by studying collective excitations in various low-dimensional systems. Collective excitations in general have the potential to tell us a great deal about a system provided we are equipped with a theory that can appropriately handle correlations. As part of this program, we will investigate the role of electronic correlations on spin-orbit coupled single/bilayer Graphene grown on transition metal dichalcogenides. It provides us with the opportunity to investigate collective excitations from non-spin degrees of freedom like sublattice, valley, and layer. We will further investigate collective excitations in the various quantum phases expected around the unconventional superconductivity phase like nematic, coexistence of nematic with superconductivity, magnetic and its coexistence with superconductivity. We will also provide the theory of Raman spectrum in all of these phases. Experimentally tracking the modes across the phase-boundaries using our theoretical model will provide improved insight into the nature of correlations present in the system. This program is designed to develop theoretical tools to handle many-body correlations in spin-orbit coupled systems: an important step forward in studying more complex phases of matter and incorporating many-body effects into fields like Spintronics and quantum computation. Several groups stand to benefit from the output of this program: it directly impacts groups working on Graphene-based devices; the high Tc community can benefit from the fact that different pairing mechanisms that predict similar ground-states, can now be distinguished as the collective excitations are different in each case; many of the conclusions we form in this program can also be tested using cold-atom set-ups thereby encouraging experiments in that field; the knowledge of collective excitations is also a stepping stone towards gauging the properties of non-equilibrium systems.

低维系统是表现出新型量子现象的有趣类别。一些引起大量嗡嗡声的示例是非常规的超导体和石墨烯基材料。他们通过帮助发现新颖的量子阶段（涉及磁性，密度波，超导性甚至在其中共存），为未来提供了巨大的希望。并用Spintronics代替电子产品：传输信息的更有效手段。在低维系统中，另一个不可避免的成分是旋转轨道耦合，它破坏了平等。当与超导性结合使用时，可能会导致诸如Majorana Fermions之类的外来激发，这对于量子计算至关重要。但是，许多兴奋一直处于单粒子物理水平。这不允许我们利用量子世界的利益发挥最大的潜力。为此，人们需要了解多体相关性在此类系统中的作用。该研究计划旨在通过研究各种低维系统中的集体激发，以非常系统的方式实现。总体而言，集体激励有可能向我们讲述一个系统，只要我们拥有可以适当处理相关性的理论。 作为该程序的一部分，我们将研究电子相关性在过渡金属二核苷中生长的自旋轨道耦合单/双层石墨烯的作用。它为我们提供了调查来自Sublattice，Valley和Layer等非旋转自由度的集体激励的机会。我们将进一步研究周围在非常规超导阶段预期的各种量子阶段中的集体激发，例如nematic，nematic与超导性，磁性，磁性及其与超导性的共存。我们还将在所有这些阶段中提供拉曼光谱理论。使用我们的理论模型在实验上跟踪整个相位模式的模式将改善对系统中存在相关性质的洞察力。 该程序旨在开发理论工具来处理旋转轨道耦合系统中的多体相关性：研究物质更复杂的阶段并将多体效应纳入静脉过程和量子计算等领域的重要一步。几个小组将从该程序的输出中受益：它直接影响基于石墨烯的设备上的组；高TC社区可以从以下事实中受益：现在可以区分相似地面国家的不同配对机制，因为在每种情况下集体激发都不同。我们在该程序中构成的许多结论也可以使用冷原子设置进行测试，从而鼓励在该领域进行实验。集体激发的知识也是衡量非平衡系统特性的垫脚石。