标题： 关于石墨烯和夸克-胶子等离子体系统中韦德曼-弗朗茨定律的违背 显示英文标题

标题： On the Wiedemann-Franz law violation in Graphene and quark-gluon plasma systems

摘要： 对在重离子碰撞（HIC）中产生的超相对论夸克-胶子等离子体（QGP）与石墨烯样品中的“准相对论”无质量电子-空穴等离子体的热力学和输运性质进行比较研究。我们观察到，单位净载流子密度的焓作为确定流体力学领域输运变量的有用物理量出现。洛伦兹比定义为热导率与电导率的比值，按温度归一化。在检查洛伦兹比是否通过一个或偏离一个来判断韦德曼-弗朗茨（WF）定律是否被遵守或违反时，我们发现从流体框架确定的洛伦兹比总是导致WF定律的违反。原因是洛伦兹比与流体中每粒子的焓之间存在比例关系。基于实验观察，石墨烯和QGP，这两个系统在低净电荷密度下由于其流体特性而表现出WF定律的违反。然而，高净电荷密度下的石墨烯遵守WF定律，这与高费米能或密度的金属类似。这表明石墨烯系统从低密度到高密度区域发生了流体到非流体的转变。在这方面，高密度下QGP的流体或非流体特性仍有待未来设施如压缩重子物质（CBM）和基于Nuclotron的离子对撞机设施（NICA）实验进一步探索。 显示英文摘要

摘要： A comparative study of the thermodynamic and transport properties of the ultra-relativistic quark-gluon plasma (QGP) produced in Heavy ion collisions (HIC) with the "quasi-relativistic" massless electron-hole plasma in graphene sample has been performed. We observe that the enthalpy per net carrier density emerges as a useful physical quantity determining the hydrodynamic domain's transport variables. Lorenz ratio is defined as thermal to electrical conductivity ratio, normalized by temperature. In searching whether the Wiedemann-Franz (WF) law is obeyed or violated by checking the Lorenz ratio as one or deviated from one, we find that the Lorenz ratio determined from the fluid-based framework will always be responsible for the violation of the WF law. The reason is the proportional relation between Lorenz ratio and enthalpy per particle in the fluid. Based on the experimental observation, graphene, and QGP, both systems at low net charge density, exhibit WF law violation due to their fluid nature. However, graphene at high net charge density obeys the WF law, followed by metals with high Fermi energy or density. It indicates a fluid to the non-fluid transition of the graphene system from low to high-density domain. In this regard, the fluid or non-fluid aspect of QGP at high density is yet to be explored by future facilities like Compressed Baryonic matter (CBM) and Nuclotron-based Ion Collider fAcility (NICA) experiments.