The holographic duality allows to construct and study models of strongly coupled quantum matter via dual gravitational theories. In general such models are characterized by the absence of quasiparticles, hydrodynamic behavior and Planckian dissipation times. One particular interesting class of quantum materials are ungapped topological semimetals which have many interesting properties from Hall transport to topologically protected edge states. We review the application of the holographic duality to this type of quantum matter including the construction of holographic Weyl semimetals, nodal line semimetals, quantum phase transition to trivial states (ungapped and gapped), the holographic dual of Fermi arcs and how new unexpected transport properties, such as Hall viscosities arise. The holographic models promise to lead to new insights into the properties of this type of quantum matter.

中文翻译：

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全息拓扑半金属

全息对偶性允许通过双重引力理论构建和研究强耦合量子物质的模型。通常，此类模型的特征在于不存在准粒子，流体动力学行为和普朗克耗散时间。一类特别有趣的量子材料是无间隙的拓扑半金属，其具有从霍尔输运到受拓扑保护的边缘态的许多令人感兴趣的特性。我们回顾了全息对偶在这种类型的量子物质上的应用，包括全息韦尔半金属，节线半金属的构造，量子相向平凡状态（无隙和有隙）的过渡，费米弧的全息对偶以及新的意外传输性质，如霍尔粘度上升。