Lifshitz transition represents a sudden reconstruction of Fermi surface structure, giving rise to anomalies in electronic properties of materials. Such a transition does not necessarily rely on symmetry-breaking and thus is topological. It holds a key to understand the origin of many exotic quantum phenomena, for example, the mechanism of extremely large magnetoresistance (MR) in topological Dirac/Weyl semimetals. Here, we report studies of the angle-dependent MR (ADMR) and the thermoelectric effect in W₂As₃ single crystal. The compound shows a large unsaturated MR (of about 7000% at 4.2 K and 53 T). The most striking finding is that the ADMR significantly deforms from the horizontal dumbbell-like shape above 40 K to the vertical lotus-like pattern below 30 K. The window of 30–40 K also corresponds substantial changes in Hall effect, thermopower and Nernst coefficient, implying an abrupt change of Fermi surface topology. Such a temperature-induced Lifshitz transition results in a compensation of electron-hole transport and the large MR as well. We thus suggest that the similar method can be applicable in detecting a Fermi-surface change of a variety of quantum states when a direct Fermi-surface measurement is not possible.

Lifshitz跃迁表示费米表面结构的突然重建，从而引起了材料电子性能的异常。这种转变不一定依赖于对称破坏，因此是拓扑结构。它是了解许多奇特的量子现象起源的关键，例如拓扑Dirac / Weyl半金属中极大的磁阻（MR）机理。在这里，我们报告了W ₂ As ₃中与角度相关的MR（ADMR）和热电效应的研究。单晶。该化合物显示出较大的不饱和MR（在4.2 K和53 T下约为7000％）。最惊人的发现是ADMR从40 K以上的水平哑铃状变形到30 K以下的垂直莲花状变形。30–40 K的窗口也对应于霍尔效应，热功率和能斯特系数的显着变化，这意味着费米表面拓扑会突然发生变化。这种由温度引起的Lifshitz跃迁会导致电子空穴传输和大MR的补偿。因此，我们建议，当不可能直接进行费米表面测量时，类似的方法可适用于检测各种量子态的费米表面变化。