Topological phase transition induced extreme magnetoresistance in TaSb$_{2}$

Zheng Wang; Yupeng Li; Yunhao Lu; Zhixuan Shen; Feng Sheng; Chunmu Feng; Yi Zheng; Zhuan Xu

paper

Topological phase transition induced extreme magnetoresistance in TaSb $_{2}$

arXiv:1603.01717

Abstract

We report extremely large positive magnetoresistance of 1.72 million percent in single crystal TaSb $_{2}$ at moderate conditions of 1.5 K and 15 T. The quadratic growth of magnetoresistance (MR $\propto B^{1.96}$ ) is not saturating up to 15 T, a manifestation of nearly perfect compensation with $< 0.1%$ mismatch between electron and hole pockets in this semimetal. The compensation mechanism is confirmed by temperature-dependent MR, Hall and thermoelectric coefficients of Nernst and Seebeck, revealing two pronounced Fermi surface reconstruction processes without spontaneous symmetry breaking, \textit{i.e.} Lifshitz transitions, at around 20 K and 60 K, respectively. Using quantum oscillations of magnetoresistance and magnetic susceptibility, supported by density-functional theory calculations, we determined that the main hole Fermi surface of TaSb $_{2}$ forms a unique shoulder structure along the $F - L$ line. The flat band top of this shoulder pocket is just a few meV above the Fermi level, leading to the observed topological phase transition at 20 K when the shoulder pocket disappears. Further increase in temperature pushes the Fermi level to the band top of the main hole pocket, induced the second Lifshitz transition at 60 K when hole pocket vanishes completely.

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Topological phase transition induced extreme magnetoresistance in TaSb2​

Abstract

Cited by in corpus (7)

Topological phase transition induced extreme magnetoresistance in TaSb $_{2}$