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Angle-dependent magnetoresistance and its implications for Lifshitz transition in W 2 As 3
npj Quantum Materials ( IF 5.4 ) Pub Date : 2019-11-29 , DOI: 10.1038/s41535-019-0197-5
Jialu Wang , Haiyang Yang , Linchao Ding , Wei You , Chuanying Xi , Jie Cheng , Zhixiang Shi , Chao Cao , Yongkang Luo , Zengwei Zhu , Jianhui Dai , Mingliang Tian , Yuke Li

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.



中文翻译:

W 2 As 3中与角度有关的磁阻及其对Lifshitz跃迁的影响

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。

更新日期:2019-11-29
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