Short-time dynamics of correlated finite fermion systems - a Nonequilibrium Green functions approach

相关有限费米子系统的短时动力学 - 非平衡格林函数方法

• 批准号: 464370560
• 负责人: Professor Dr. Michael Bonitz
• 金额: --
• 依托单位: Department of Physics
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/464370560?language=en
• 关键词: Short; time; dynamics; correlated; finite

Nonequilibrium quantum dynamics of many-body and few-body systems remains one of the unresolved problems of theoretical physics. Recently this topic gained new interest due to novel applications and experiments in a broad range of fields ranging from ultracold atoms to condensed matter as well as to dense plasmas and atomic and molecular systems. Experimental progress giving time-resolved access to new observables well beyond average thermodynamic quantities of macroscopic systems poses a considerable challenge to theory. Accurate modeling of interacting quantum many-body systems far from equilibrium is very challenging due to the large number of independent variables and the breakdown of perturbative approaches that would allow to use ground state or equilibrium results as an input. Moreover, the simultaneous presence of multiple time scales governing nonequilibrium dynamics, the importance of correlations and finite size effects is challenging for the applicability of any given advanced method. The initial stage of excitation, collisional redistribution, and onset of relaxation is particularly difficult to describe adequately, requiring advanced methods of many-body theory. However, these methods are computationally expensive and, therefore, until now, have been restricted to short time scales or/and small system sizes. The present project aims to significantly relieve these restrictions, taking advantage of recent breakthroughs in the field of nonequilibrium Green functions. Aside from the development of theoretical methods the project will obtain new results for the short-time dynamics of graphene nanoribbon heterostructures exposed to short laser pulses that fully take into account electronic correlations.

多体和少体系统的非平衡量子动力学一直是理论物理中未解决的问题之一。近年来，由于在超冷原子、凝聚态物质、致密等离子体、原子和分子系统等广泛领域的新应用和实验，这一主题获得了新的兴趣。实验进展使时间分辨获得远超过宏观系统平均热力学量的新观测，这对理论提出了相当大的挑战。由于大量的自变量和允许使用基态或平衡结果作为输入的摄动方法的破坏，对远离平衡的相互作用量子多体系统的精确建模非常具有挑战性。此外，控制非平衡动力学的多个时间尺度同时存在，相关性的重要性和有限尺寸效应对任何给定的先进方法的适用性都是一个挑战。激发的初始阶段，碰撞再分布和松弛的开始特别难以充分描述，需要先进的多体理论方法。然而，这些方法在计算上是昂贵的，因此，到目前为止，一直局限于短时间尺度或/和小系统尺寸。本项目旨在利用非平衡格林函数领域的最新突破，显著缓解这些限制。除了发展理论方法外，该项目还将获得充分考虑电子相关性的短激光脉冲下石墨烯纳米带异质结构的短时间动力学的新结果。