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arXiv · 1812.11902

ω/T scaling and magnetic quantum criticality in BaFe2(As0.7P0.3)2

Ding Hu·Haoyu Hu·Wenliang Zhang·Yuan Wei·Shiliang Li·Yanhong Gu·Xiaoyan Ma·Douglas L. Abernathy·Songxue Chi·Travis J. Williams·Yu Li·Qimiao Si·Pengcheng Dai
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Abstract

We used transport and inelastic neutron scattering to study the optimally phosphorus-doped BaFe$_2$(As$_{0.7}$P$_{0.3}$)$_2$ superconductor ($T_c = 30$ K). In the normal state, we find that the previously reported linear temperature dependence of the resistivity below room temperature extends to $\sim$ 500 K. Our analysis of the temperature and energy ($E=\hbarω$) dependence of spin dynamical susceptibility at the antiferromagnetic (AF) ordering wave vector $χ^{\prime\prime}({\bf Q}_{\rm AF},ω)$ reveal an $ω/ T$ scaling within $1.1<E/k_BT<110$. These results suggest that the linear temperature dependence of the resistivity is due to the presence of a magnetic quantum critical point in the cleanest iron pnictides near optimal superconductivity. Moreover, the results reconcile the strange-metal temperature dependences with the weakly first-order nature of the quantum transition out of the AF and nematic orders.

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Ding Hu, Haoyu Hu, Wenliang Zhang, Yuan Wei, Shiliang Li, Yanhong Gu, Xiaoyan Ma, Douglas L. Abernathy, Songxue Chi, Travis J. Williams, Yu Li, Qimiao Si, Pengcheng Dai. 2018-12-31. ω/T scaling and magnetic quantum criticality in BaFe2(As0.7P0.3)2. https://arxiv.org/abs/1812.11902

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