arXivDaily arXiv每日学术速递 周一至周五更新
arXiv周末暂无论文更新,休息一下吧,周末愉快~~
arXiv 1903.05652cond-mat.str-elcond-mat.mes-hall
收藏

多边形费米面的电子流体力学

Electron hydrodynamics with a polygonal Fermi surface

Caleb Q. Cook, Andrew Lucas

摘要:

最近的实验已经在许多材料中观察到了流体动力学电子流的迹象,并非所有材料都具有各向同性的费米表面。我们重新审视这些实验在$\mathrm{PdCoO}_2$,准二维材料的费米表面是一个圆形的六边形,并观察到的数据出现定量一致的非流体动力学的解释。然而,这样的实验的动机,我们开发了一个简单的模型的低温动力学和流体力学的二维费米液体与多边形费米表面。几何效应导致有限数量的额外的长寿命的准流体动力学的“不平衡”模式和相应的质的变化,在运输弹道流体动力学交叉。在流体力学极限,我们发现非相干扩散和一个新的耗散组件的粘度张量所产生的明确打破旋转不变性的费米面。最后,我们计算的电导窄通道跨越弹道流体动力学交叉,并证明了修改的Gurzhi效应,允许非单调的温度和宽度依赖的通道电导。

英文摘要:

Recent experiments have observed hints of hydrodynamic electron flow in a number of materials, not all of which have an isotropic Fermi surface. We revisit these experiments in $\mathrm{PdCoO}_2$, a quasi-two-dimensional material whose Fermi surface is a rounded hexagon, and observe that the data appears quantitatively consistent with a non-hydrodynamic interpretation. Nevertheless, motivated by such experiments, we develop a simple model for the low temperature kinetics and hydrodynamics of a two-dimensional Fermi liquid with a polygonal Fermi surface. A geometric effect leads to a finite number of additional long-lived quasihydrodynamic "imbalance" modes and corresponding qualitative changes in transport at the ballistic-to-hydrodynamic crossover. In the hydrodynamic limit, we find incoherent diffusion and a new dissipative component of the viscosity tensor arising from the explicit breaking of rotational invariance by the Fermi surface. Finally, we compute the conductance of narrow channels across the ballistic-to-hydrodynamic crossover and demonstrate a modification of the Gurzhi effect that allows for non-monotonic temperature and width dependence in the channel conductance.

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。

↑