High pressure quantum oscillation measurement of the pressure-induced iron-based superconductor and development of 4GPa class high pressure apparatus

本文研究了高压下EuFe_2As_2超导体的输运性质和量子振荡效应。电阻率，霍尔效应，和上临界场的详细分析表明，没有发散的准粒子有效质量在临界压力Pc的磁性和结构转变消失。另一方面，我们已经表明，电子和空穴的散射率是近似T-线性的P>Pc。恢复费米液体的T2依赖性的电阻率在高场清楚地表明，自旋涨落的起源的异常散射。此外，我们还研究了压力演化的Shubnikov-de哈斯频率和准粒子有效质量。

We have investigated transport properties and quantum oscillation effect in the pressure-induced superconductor EuFe2As2 under high pressure. Detailed analyses of the resistivity, Hall effect, and upper critical field indicate no divergence of quasiparticle effective mass at the critical pressure Pc where the magnetic and structural transition disappears. On the other hand, we have shown that the scattering rates for both electrons and holes are approximately T-linear for P>Pc. The recovery of the Fermi liquid-like T2 dependence of resistivity at high fields clearly indicates that spin fluctuations are the origin of the anomalous scattering. In addition, we have studied pressure evolutions of the Shubnikov-de Haas frequencies and quasiparticle effective mass.