Phase Diagram of Graphene from Lattice Field Theory

晶格场论的石墨烯相图

• 批准号: 276822021
• 负责人: Dr. Pavel Buividovich, Ph.D.
• 金额: --
• 依托单位: Institut für Theoretische Physik
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2015
• 资助国家: 德国
• 起止时间: 2014-12-31 至 2018-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/276822021?language=en
• 关键词: Phase; Diagram; Graphene; Lattice; Field

This project exploits analogies between the electronic properties of graphene and strongly coupled quantum field theories, most importantly quantum chromodynamics (QCD), to address some of the outstanding questions in relation to many-body strong-coupling effects which can nowadays increasingly well be studied experimentally in high quality samples of graphene. Ab-initio Monte-Carlo simulations based on our state-of-the-art tools from lattice field theory are used tosystematically explore the phase structure of graphene in the presence of external influences which favor various ordered phases. Dyson-Schwinger equations on the graphene lattice complement these ab-initio calculations, e.g., for pseudo-conformal behavior in very large volumes or finite charge-carrier densities where there is a fermion-sign problem as in QCD at finite baryon density. In particular, the project aims to determine which of the various Mott insulating phases occur inthe various regions of tunable parameters and whether they can be realized experimentally. It thereby addresses magnetic fields and magnetic catalysis as also relevant in heavy-ion collisions, defects as catalysts for pre-condensation and their analogies with instantons, the finite-density Lifshitz transition, and the relation between Anderson localization and chiral symmetry breaking as in hot QCD. The goal is to identify how graphene can best be used to test such non-perturbative quantum field theory concepts as also relevant for studies of the QCD phase diagram under well controllable experimental conditions.

该项目利用石墨烯的电子性质与强耦合量子场论（最重要的是量子色动力学（QCD））之间的类比，来解决与多体强耦合效应相关的一些悬而未决的问题，这些问题如今可以越来越好地进行实验研究在高质量的石墨烯样品中。 基于我们最先进的晶格场理论工具，采用从头算蒙特-卡罗模拟方法，系统地研究了石墨烯在各种有序相存在下的相结构.石墨烯晶格上的Dyson-Schwinger方程补充了这些从头计算，例如，对于在非常大的体积或有限的电荷载流子密度中的伪共形行为，其中存在有限重子密度下的QCD中的费米子符号问题。特别是，该项目的目的是确定哪些各种莫特绝缘阶段发生在可调参数的各个区域，以及它们是否可以通过实验实现。因此，它解决磁场和磁催化也相关的重离子碰撞，缺陷作为催化剂的预凝聚和他们的类比与瞬子，有限密度Lifshitz过渡，和安德森本地化和手征对称性破缺之间的关系，在热QCD。我们的目标是确定如何最好地使用石墨烯来测试这种非微扰量子场论概念，也相关的QCD相图在可控的实验条件下的研究。