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arXiv 1610.02459cond-mat.mes-hallcond-mat.other
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Dirac半金属Cd3As2中的反常能斯特效应

Anomalous Nernst Effect in Dirac Semimetal Cd3As2

Tian Liang, Jingjing Lin, Quinn Gibson, Tong Gao, Max Hirschberger, Minhao Liu, R. J. Cava, N. P. Ong

摘要:

狄拉克和外尔半金属显示出许多新颖的性质。在Cd $_3$ As $_2$中,狄拉克节点导致了一种保护机制,该机制强烈抑制了零磁场中的反向散射,从而导致电子迁移率($\sim$ 10 $^7$ cm $^2$ V $^{-1}$ s $^{-1}$)。在外加磁场中,与外尔节点相关的Berry曲率将产生反常的能斯特效应。我们观察到一个大的异常能斯特效应在镉$_3$作为$_2$。反常能斯特信号和输运弛豫时间$τ_{tr}$在$\sim$ 50 K开始迅速增加。这表明保护机制与反常能斯特效应有密切关系。在一个场中,体态的量子振荡显示出拍频效应,这表明狄拉克节点分裂成外尔态,从而使贝瑞曲率可以作为异常的能斯特效应被观察到。

英文摘要:

Dirac and Weyl semimetals display a host of novel properties. In Cd$_3$As$_2$, the Dirac nodes lead to a protection mechanism that strongly suppresses backscattering in zero magnetic field, resulting in ultrahigh mobility ($\sim$ 10$^7$ cm$^2$ 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 Cd$_3$As$_2$. Both the anomalous Nernst signal and transport relaxation time $τ_{tr}$ begin to increase rapidly at $\sim$ 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.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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