In the presence of interactions, electrons in condensed-matter systems can behave hydrodynamically, exhibiting phenomena associated with classical fluids, such as vortices and Poiseuille flow^1,2,3. In most conductors, electron–electron interactions are minimized by screening effects, hindering the search for hydrodynamic materials; however, recently, a class of semimetals has been reported to exhibit prominent interactions^4,5. Here we study the current flow in the layered semimetal tungsten ditelluride by imaging the local magnetic field using a nitrogen-vacancy defect in a diamond. We image the spatial current profile within three-dimensional tungsten ditelluride and find that it exhibits non-uniform current density, indicating hydrodynamic flow. Our temperature-resolved current profile measurements reveal a non-monotonic temperature dependence, with the strongest hydrodynamic effects at approximately 20 K. We also report ab initio calculations showing that electron–electron interactions are not explained by the Coulomb interaction alone, but are predominantly mediated by phonons. This provides a promising avenue in the search for hydrodynamic flow and prominent electron interactions in high-carrier-density materials.

在存在相互作用的情况下，凝聚态系统中的电子可以表现出流体动力学，表现出与经典流体相关的现象，例如涡流和泊肃叶流^1,2,3。在大多数导体中，电子-电子相互作用被屏蔽效应最小化，阻碍了对流体动力材料的研究；然而，最近，据报道一类半金属表现出显着的相互作用^4,5. 在这里，我们通过使用金刚石中的氮空位缺陷对局部磁场进行成像来研究层状半金属二碲化钨中的电流。我们对三维二碲化钨内的空间电流分布进行成像，发现它表现出不均匀的电流密度，表明流体动力流动。我们的温度分辨电流分布测量揭示了非单调的温度依赖性，在大约 20 K 处具有最强的流体动力学效应。我们还报告了从头算计算表明电子 - 电子相互作用不能单独由库仑相互作用来解释，而是主要介导通过声子。这为在高载流子密度材料中寻找流体动力流动和显着电子相互作用提供了一条有希望的途径。