Anomalous Nernst Effect in Dirac Semimetal Cd3As2

2016/10/31 by Tian Liang, Jingjing Lin, Quinn Gibson +5 · 1 citation
Physics and Astronomy · #cond-mat.mes-hall #cond-mat.other

paper · pdf · doi:10.1103/physrevlett.118.136601

published as Phys. Rev. Lett. 118, 136601 (2017) · 13 pages, 7 figures

arxiv created 2017/09/20 · arxiv updated 2017/09/21

Abstract

Dirac and Weyl semimetals display a host of novel properties. In Cd₃As₂, the Dirac nodes lead to a protection mechanism that strongly suppresses backscattering in zero magnetic field, resulting in ultrahigh mobility (∼ 10⁷ cm² V^-1 s^-1). In applied magnetic field, an anomalous Nernst effect is predicted to arise from the Berry curvature associated with the Weyl nodes. We report observation of a large anomalous Nernst effect in Cd₃As₂. Both the anomalous Nernst signal and transport relaxation time τ_tr begin to increase rapidly at ∼ 50 K. This suggests a close relation between the protection mechanism and the anomalous Nernst effect. In a field, the quantum oscillations of bulk states display a beating effect, suggesting that the Dirac nodes split into Weyl states, allowing the Berry curvature to be observed as an anomalous Nernst effect.

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