超纯PdCoO $_{2}$的非局域电动力学
Non-local electrodynamics in ultra-pure PdCoO$_{2}$
摘要：
电子在绝大多数导体中的运动是扩散的，服从欧姆定律。然而，最近发现和增长的高纯度材料具有极长的电子平均自由程，引发了对非欧姆替代品，包括粘性和弹道流的兴趣。虽然非欧姆输运机制已经在一系列材料中被发现，包括二维电子气、石墨烯、拓扑半金属和铜铁矿金属，但确定它们的性质已被证明是具有挑战性的。在这里，我们报告了一种新的方法来解决这个问题，采用宽带微波光谱的铜铁矿金属PdCoO $_{2}$在三个不同的样品几何形状，将是相同的扩散运输。所观察到的差异，其中去至于不同的幂律，利用六方对称的PdCoO $_{2}$。这允许一个特别优雅的基于非局部电动力学的诊断，其结果有利于弹道严格流体动力学流。此外，它揭示了一个新的效果弹道电子流，由于高度刻面的形状的六角费米表面。我们结合我们广泛的数据集与玻尔兹曼方程的分析，以表征在PdCoO $_{2}$的非本地制度。更广泛地说，我们的研究结果突出了宽带微波光谱在研究新一代超高电导率材料中的奇异输运机制方面发挥核心作用的潜力。
英文摘要：
The motion of electrons in the vast majority of conductors is diffusive, obeying Ohm's law. However, the recent discovery and growth of high-purity materials with extremely long electronic mean free paths has sparked interest in non-ohmic alternatives, including viscous and ballistic flow. Although non-ohmic transport regimes have been discovered across a range of materials, including two-dimensional electron gases, graphene, topological semimetals, and the delafossite metals, determining their nature has proved to be challenging. Here, we report on a new approach to the problem, employing broadband microwave spectroscopy of the delafossite metal PdCoO$_{2}$ in three distinct sample geometries that would be identical for diffusive transport. The observed differences, which go as far as differing power laws, take advantage of the hexagonal symmetry of PdCoO$_{2}$. This permits a particularly elegant symmetry-based diagnostic for non-local electrodynamics, with the result favouring ballistic over strictly hydrodynamic flow. Furthermore, it uncovers a new effect for ballistic electron flow, owing to the highly facetted shape of the hexagonal Fermi surface. We combine our extensive dataset with an analysis of the Boltzmann equation to characterize the non-local regime in PdCoO$_{2}$. More broadly, our results highlight the potential of broadband microwave spectroscopy to play a central role in investigating exotic transport regimes in the new generation of ultra-high conductivity materials.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
